Targeting of oncogenic AAA-ATPase TRIP13 reduces progression of pancreatic ductal adenocarcinoma

Thyroid hormone receptor-interacting protein 13 (TRIP13) is involved in cancer progression, but its role in pancreatic ductal adenocarcinoma (PDAC) is unknown. Thus, we assessed the expression, functional role, and mechanism of action of TRIP13 in PDAC. We further examined the efficacy of TRIP13 inhibitor, DCZ0415, alone or in combination with gemcitabine on malignant phenotypes, tumor progression, and immune response. We found that TRIP13 was overexpressed in human PDACs relative to corresponding normal pancreatic tissues. TRIP13 knockdown or treatment of PDAC cells with DCZ0415 reduced proliferation and colony formation, and induced G2/M cell cycle arrest and apoptosis. Additionally, TRIP13 knockdown or targeting with DCZ0415 reduced the migration and invasion of PDAC cells by increasing E-cadherin and decreasing N-cadherin and vimentin. Pharmacologic targeting or silencing of TRIP13 also resulted in reduce expression of FGFR4 and STAT3 phosphorylation, and downregulation of the Wnt/β-catenin pathway. In immunocompromised mouse models of PDAC, knockdown of TRIP13 or treatment with DCZ0415 reduced tumor growth and metastasis. In an immunocompetent syngeneic PDAC model, DCZ0415 treatment enhanced the immune response by lowering expression of PD1/PDL1, increasing granzyme B/perforin expression, and facilitating infiltration of CD3/CD4 T-cells. Further, DCZ0415 potentiated the anti-metastatic and anti-tumorigenic activities of gemcitabine by reducing proliferation and angiogenesis and by inducing apoptosis and the immune response. These preclinical findings show that TRIP13 is involved in PDAC progression and targeting of TRIP13 augments the anticancer effect of gemcitabine.

BZW2 Inhibition Reduces Colorectal Cancer Growth and Metastasis

Because survival of patients with metastatic colorectal cancer remain poor, there is an urgent need to identify potential novel druggable targets that are associated with colorectal cancer progression. One such target, basic leucine zipper and W2 domains 2 (BZW2), is involved in regulation of protein translation, and its overexpression is associated with human malignancy. Thus, we investigated the expression and regulation of BZW2, assessed its role in activation of WNT/β-catenin signaling, identified its downstream molecules, and demonstrated its involvement in metastasis of colorectal cancer. In human colorectal cancers, high mRNA and protein expression levels of BZW2 were associated with tumor progression. BZW2-knockdown reduced malignant phenotypes, including cell proliferation, invasion, and spheroid and colony formation. BZW2-knockdown also reduced tumor growth and metastasis; conversely, transfection of BZW2 into BZW2 low-expressing colorectal cancer cells promoted malignant features, including tumor growth and metastasis. BZW2 expression was coordinately regulated by microRNA-98, c-Myc, and histone methyltransferase enhancer of zeste homolog 2 (EZH2). RNA sequencing analyses of colorectal cancer cells modulated for BZW2 identified P4HA1 and the long noncoding RNAs, MALAT1 and NEAT1, as its downstream targets. Further, BZW2 activated the Wnt/β-catenin signaling pathway in colorectal cancers expressing wild-type β-catenin. In sum, our study suggests the possibility of targeting BZW2 expression by inhibiting EZH2 and/or c-Myc.

IMPLICATIONS

FDA-approved small-molecule inhibitors of EZH2 can indirectly target BZW2 and because BZW2 functions as an oncogene, these inhibitors could serve as therapeutic agents for colorectal cancer.

Microbiome diversity in African American, European American, and Egyptian colorectal cancer patients

Purpose

Although there is an established role for microbiome dysbiosis in the pathobiology of colorectal cancer (CRC), CRC patients of various race/ethnicities demonstrate distinct clinical behaviors. Thus, we investigated microbiome dysbiosis in Egyptian, African American (AA), and European American (EA) CRC patients.

Patients and methods

CRCs and their corresponding normal tissues from Egyptian (n = 17) patients of the Alexandria University Hospital, Egypt, and tissues from AA (n = 18) and EA (n = 19) patients at the University of Alabama at Birmingham were collected. DNA was isolated from frozen tissues, and the microbiome composition was analyzed by 16S rRNA sequencing. Differential microbial abundance, diversity, and metabolic pathways were identified using linear discriminant analysis (LDA) effect size analyses. Additionally, we compared these profiles with our previously published microbiome data derived from Kenyan CRC patients.

Results

Differential microbiome analysis of CRCs across all racial/ethnic groups showed dysbiosis. There were high abundances of Herbaspirillum and Staphylococcus in CRCs of Egyptians, Leptotrichia in CRCs of AAs, Flexspiria and Streptococcus in CRCs of EAs, and Akkermansia muciniphila and Prevotella nigrescens in CRCs of Kenyans (LDA score >4, adj. p-value <0.05). Functional analyses showed distinct microbial metabolic pathways in CRCs compared to normal tissues within the racial/ethnic groups. Egyptian CRCs, compared to normal tissues, showed lower l-methionine biosynthesis and higher galactose degradation pathways.

Conclusions

Our findings showed altered mucosa-associated microbiome profiles of CRCs and their metabolic pathways across racial/ethnic groups. These findings provide a basis for future studies to link racial/ethnic microbiome differences with distinct clinical behaviors in CRC.

Molecular Subtyping and Survival Analysis of Osteosarcoma Reveals Prognostic Biomarkers and Key Canonical Pathways

Osteosarcoma (OS) is a common bone malignancy in children and adolescents. Although histological subtyping followed by improved OS treatment regimens have helped achieve favorable outcomes, a lack of understanding of the molecular subtypes remains a challenge to characterize its genetic heterogeneity and subsequently to identify diagnostic and prognostic biomarkers for developing effective treatments. In the present study, global analysis of DNA methylation, and mRNA and miRNA gene expression in OS patient samples were correlated with their clinical characteristics. The mucin family of genes, MUC6, MUC12, and MUC4, were found to be highly mutated in the OS patients. Results revealed the enrichment of molecular pathways including Wnt signaling, Calcium signaling, and PI3K-Akt signaling in the OS tumors. Survival analyses showed that the expression levels of several genes such as RAMP1, CRIP1, CORT, CHST13, and DDX60L, miRNAs and lncRNAs were associated with survival of OS patients. Molecular subtyping using Cluster-Of-Clusters Analysis (COCA) for mRNA, lncRNA, and miRNA expression; DNA methylation; and mutation data from the TARGET dataset revealed two distinct molecular subtypes, each with a distinctive gene expression profile. Between the two subtypes, three upregulated genes, POP4, HEY1, CERKL, and seven downregulated genes, CEACAM1, ABLIM1, LTBP2, ISLR, LRRC32, PTPRF, and GPX3, associated with OS metastasis were found to be differentially regulated. Thus, the molecular subtyping results provide a strong basis for classification of OS patients that could be used to develop better prognostic treatment strategies.

A high-resolution 3D atlas of the spectrum of tuberculous and COVID-19 lung lesions

Our current understanding of the spectrum of TB and COVID-19 lesions in the human lung is limited by a reliance on low-resolution imaging platforms that cannot provide accurate 3D representations of lesion types within the context of the whole lung. To characterize TB and COVID-19 lesions in 3D, we applied micro/nanocomputed tomography to surgically resected, postmortem, and paraffin-embedded human lung tissue. We define a spectrum of TB pathologies, including cavitary lesions, calcium deposits outside and inside necrotic granulomas and mycetomas, and vascular rearrangement. We identified an unusual spatial arrangement of vasculature within an entire COVID-19 lobe, and 3D segmentation of blood vessels revealed microangiopathy associated with hemorrhage. Notably, segmentation of pathological anomalies reveals hidden pathological structures that might otherwise be disregarded, demonstrating a powerful method to visualize pathologies in 3D in TB lung tissue and whole COVID-19 lobes. These findings provide unexpected new insight into the spatial organization of the spectrum of TB and COVID-19 lesions within the framework of the entire lung.

A signature of Prevotella copri and Faecalibacterium prausnitzii depletion, and a link with bacterial glutamate degradation in the Kenyan colorectal cancer patients

BACKGROUND

Colorectal cancer (CRC) is the fifth most diagnosed cancer in Sub-Saharan Africa. In Kenya, CRC incidence rates tripled from 1997 to 2017. In the Moi Teaching and Referral Hospital, Moi University, there has been an increase in CRC cases, notably for younger patients. A suggested pathobiology for this increase is gut microbiome dysbiosis. Since, for the Kenyan CRC patient population, microbiome studies are rare, there is a need for a better understanding of how microbiome dysbiosis influences CRC epidemiology in Kenya. In this single-center study, the focus was on profiling the gut microbiome of Kenyan CRC patients and healthy volunteers and evaluating associations between microbiome profiles and the age of CRC patients.

METHODS

The gut mucosa-associated microbiome of 18 CRC patients and 18 healthy controls were determined by 16S rRNA sequencing and analyzed for alpha and beta diversity, differential abundance, and microbial metabolic profiling.

RESULTS

Alpha diversity metrics showed no significant differences, but beta diversity metrics showed dissimilarities in the microbial communities between CRC patients and healthy controls. The most underrepresented species in the CRC group were Prevotella copri (P. copri) and Faecalibacterium prausnitzii (F. prausnitzii), although Bacteroides fragilis (B. fragilis) and Prevotella nigrescens were overrepresented (linear discriminant analysis, LDA score >2, P<0.05). Also, for CRC patients, significant metagenomic functional alterations were evident in microbial glutamate metabolic pathways (L-glutamate degradation VIII was enriched, and L-glutamate and L-glutamine biosynthesis were diminished) (P<0.05, log2 Fold Change >1). Moreover, the microbiome composition was different for patients under 40 years of age compared to older patients (LDA score >2, P<0.05).

CONCLUSIONS

Microbiome and microbial metabolic profiles of CRC patients are different from those of healthy individuals. CRC microbiome dysbiosis, particularly P. copri and F. prausnitzii depletion and glutamate metabolic alterations, are evident in Kenyan CRC patients.

Reducing regorafenib toxicity by combining with dual JAK-HDAC inhibitor in colorectal cancer

e15597

Background: In the US, colorectal cancer (CRC) is the third most common cancer. Patients receiving regorafenib, a multiple-kinase inhibitor, recommended to manage metastatic CRCs (mCRCs), has a modest improvement in median overall survival but it is associated with several toxicities. Our present study addresses regorafenib-induced toxicity concerns by combining regorafenib with a novel dual JAK-HDAC inhibitor (JAK-HDACi). The rationale for the dual inhibitor drug selection is due to the facts that the JAK/STAT/SOCS pathway is modulated in CRCs, and concurrent inhibition of JAK sensitizes solid tumors to HDACi. This study focused on evaluating the efficacy and reducing regorafenib-induced toxicity with this novel therapeutic combination in CRC preclinical models. Methods: We evaluated the toxicity of the JAK-HDACi, regorafenib, and their combination in normal colonic cells (CRL-1807) and their efficacy in CRC cell lines (HCT116, RKO, HT29, and SW480) exhibiting various statuses of p53, KRAS, BRAF, EGFR, and microsatellite instability, by conducting colony formation, cell proliferation, and cell cycle arrest assays. Kinome profiling and whole transcriptomic analysis were performed. Their efficacy was assessed in vivo in a CRC patient-derived xenograft (PDX) model, and experimental metastasis was evaluated in NSG mice using luciferase-tagged HT29 cells. Non-invasive, whole-body bioluminescence imaging was performed. Tumor tissues were harvested and stored at −80°C or prepared formalin-fixed paraffin-embedded blocks for Hematoxylin and Eosin (H&E) and immunostaining. Serum analysis was performed to evaluate liver and kidney functions to assess the toxicity. Results: At 500 nM concentrations, there was no pronounced death of CRL-1807 cells, but reduced number of colonies in CRC cells. Drug treatments decreased phosphorylation of STAT3 and ERK1/2 and cell viability, wherein the reduction was robust in the combination. The combination reduced activity of various kinases, as evident through kinome profiling. In SW480 cells, the combination caused G0-G1 cell arrest and decreased the S phase. RNA-seq results revealed modulation of key pathways: apoptosis, ECM-receptor interaction, and focal adhesion. The PDX model showed that the combination treatment reduced tumor growth, as evidenced in H&E staining with higher necrosis and reduced Ki67 staining. Experimental metastasis, bioluminescence imaging, and histological examination showed pronounced reduction in metastasis in mice treated with the combination. Serum chemistry profiles showed that the treatments did not cause systemic toxicity to mice used in either model. Conclusions: The combination therapy with the JAK-HDACi and regorafenib was more effective than the single agents with no evident toxicity. These findings lend credence to a clinical trial to assess this combination for treatment of patients with advanced CRC.

DCZ0415, a small-molecule inhibitor targeting TRIP13, inhibits EMT and metastasis via inactivation of the FGFR4/STAT3 axis and the Wnt/β-catenin pathway in colorectal cancer

Thyroid receptor-interacting protein 13 (TRIP13), a protein of the AAA-ATPase family, is upregulated in various human cancers, including colorectal cancer (CRC). This study focused on the inhibition of TRIP13-induced CRC progression and signalling by DCZ0415, a small molecule targeting TRIP13. It demonstrated potent antitumour activity in TRIP13-deregulated cancer cell lines, regardless of their p53, KRAS, BRAF, epidermal growth factor receptor or microsatellite instability status. The treatment of CRC cells with DCZ0415 resulted in decreased cell proliferation, induced cell cycle arrest in the G2-M phase and increased apoptosis. DCZ0415 diminished xenograft tumour growth and metastasis of CRC in immunocompromised mice. DCZ0415 reduced expression of fibroblast growth factor receptor 4 (FGFR4), signal transducer and activator of transcription 3 (STAT3), and proteins associated with the epithelial-mesenchymal transition and nuclear factor kappa B (NF-κB) pathways in cells and xenografts exhibiting high expression of TRIP13. Additionally, DCZ0415 decreased cyclin D1, β-catenin and T-cell factor 1, leading to the inactivation of the Wnt/β-catenin pathway. In a syngeneic CRC model, DCZ0415 treatment induced an immune response by decreasing PD1 and CTLA4 levels and increasing granzyme B, perforin and interferon gamma. In sum, DCZ04145 inhibits the TRIP13-FGFR4-STAT3 axis, inactivates NF-κB and Wnt/β-catenin signalling, activates antitumour immune response and reduces the progression and metastasis of CRC. This study provides a rationale to evaluate DCZ0415 clinically for the treatment of a subset of CRCs that exhibit dysregulated TRIP13 and FGFR4.

Gastrointestinal Manifestations of COVID-19 Infection: Clinicopathologic Findings in Intestinal Resections Performed at Single Institution

It is now known that COVID-19 not only involves the lungs, but other organs as well including the gastrointestinal tract. Although clinic-pathological features are well-described in lungs, the histopathologic features of gastrointestinal involvement in resection specimens are not well characterized. Herein, we describe in detail the clinicopathologic features of intestinal resection specimens in four patients with COVID-19 infection. COVID-19 viral particles by in situ hybridization and immunofluorescence studies are also demonstrated. All four patients were males, aged 28–46 years, with comorbidities. They initially presented with a severe form of pulmonary COVID-19 and showed gastrointestinal symptoms, requiring surgical intervention. Histopathologic examination of resected GI specimens, mostly right colectomies, revealed a spectrum of disease, from superficial mucosal ischemic colitis to frank transmural ischemic colitis and associated changes consistent with pneumatosis cystoides intestinalis. Three patients were African American (75%), and one was Caucasian (25%); three patients died due to complications of their COVID-19 infection (75%), while one ultimately recovered from their GI complications (25%), but experienced prolonged sequela of COVID-19 infection including erectile dysfunction. In conclusion, COVID-19 infection, directly or indirectly, can cause ischemic gastrointestinal complications, with predilection for the right colon.

Age-Dependent Heterogeneity of Lymph Node Metastases and Survival Identified by Analysis of a National Breast Cancer Registry

Background:

Methods:

Results:

Conclusions:

Immunophenotype-associated gene signature in ductal breast tumors varies by receptor subtype, but the expression of individual signature genes remains consistent

BACKGROUND

In silico deconvolution of invasive immune cell infiltration in bulk breast tumors helps characterize immunophenotype, expands treatment options, and influences survival endpoints. In this study, we identify the differential expression (DE) of the LM22 signature to classify immune-rich and -poor breast tumors and evaluate immune infiltration by receptor subtype and lymph node metastasis.

METHODS

Using publicly available data, we applied the CIBERSORT algorithm to estimate immune cells infiltrating the tumor into immune-rich and immune-poor groups. We then tested the association of receptor subtype and nodal status with immune-rich/poor phenotype. We used DE to test individual signature genes and over-representation analysis for related pathways.

RESULTS

CCL19 and CXCL9 expression differed between rich/poor signature groups regardless of subtype. Overexpression of CHI3L2 and FES was observed in triple negative breast cancers (TNBCs) relative to other subtypes in immune-rich tumors. Non-signature genes, LYZ, C1QB, CORO1A, EVI2B, GBP1, PSMB9, and CD52 were consistently overexpressed in immune-rich tumors, and SCUBE2 and GRIA2 were associated with immune-poor tumors. Immune-rich tumors had significant upregulation of genes/pathways while none were identified in immune-poor tumors.

CONCLUSIONS

Overall, the proportion of immune-rich/poor tumors differed by subtype; however, a subset of 10 LM22 genes that marked immune-rich status remained the same across subtype. Non-LM22 genes differentially expressed between the phenotypes suggest that the biologic processes responsible for immune-poor phenotype are not yet well characterized.

Acute Liver Failure in a Healthy Young Female With COVID-19

Several well-described manifestations of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been reported. Among them, a transient elevation of liver enzymes is the typical presentation of coronavirus disease 2019 (COVID-19) liver-related injury. The mechanism of liver involvement is likely a combination of viral injury and immune-mediated inflammation. In contrast, acute liver failure in the setting of COVID-19 has rarely been reported. Herein, we report a case of pediatric acute liver failure in a previously healthy female adolescent infected with SARS-CoV-2 with biopsy evidence of replicating virus in hepatocytes, which has not been previously reported.

Abstract LB249: Development of 3D organoid raft cultures of colon cancer as a model to screen the therapeutic efficacy of PRIMA-1Met (APR-246)

Background: Cancer is among the leading causes of death worldwide. Hence, new drugs and faster screening models are needed. However, costly experiments for determining the therapeutic efficacy of drugs in animals before they reach clinical trials make the process difficult. To address this issue, we developed an alternative strategy to screen drugs against human tumors. 3D tumor organoids are termed Organoid Raft Cultures (ORCs) due to the strategy involved in culturing tumors ex vivo on collagen beds with grid supports to maintain their morphological structure and molecular makeup. Methodology: After receiving informed consent of patients and IRB approval at the University of Alabama at Birmingham, patients with histologically confirmed colon cancers were recruited. Portions of collected colon tumors were then implanted into the flanks of mice to generate Patient-Derived Xenografts (PDXs). Once their volumes reached 2000 mm2, tumors were excised, and ORCs were generated. This approach addresses two concerns: 1) how well are the morphological features retained when the tumors are grown ex vivo, and 2): can we accomplish faster screening of the efficacy of drugs. In the present study, we used a tumor in which we identified, by DNA-sequencing, a TP53 missense mutation at amino acid R248Q (a change from arginine to glutamine). We tested PRIMA-1Met (APR-246), an agent that reactivates mutant p53 by causing a conformational change and restores its function as a tumor suppressor. Excised xenograft tumor tissue was cut into small pieces and seeded on mucosa-stromal equivalent consisting of buffered collagen and fibroblasts in 24-well plates and allowed to grow for 2-3 days. Next, the tissue assembly was detached and placed on raft shaped stainless steel grids in 6-well plates containing ORC media. These cultures, termed ORCs, were then divided into groups of APR-246 treated and untreated. After 7 days, tissues were formalin fixed, and slides of 5-micron thickness were cut for Hematoxylin and eosin (H&E), p53 and TUNEL staining. Results: H&E staining of PDXs and ORCs showed the normal glandular morphology of colon cancers. This conventional characteristic of adenocarcinoma was retained along with other morphologic features, indicating the usefulness of ORCs. Additionally, comparisons of p53 and TUNEL staining of untreated vs APR-246-treated ORCs showed that lack of nuclear accumulation of mutant p53 in this p53 mutant tissue and induced apoptosis by APR-246 treatment, indicating the efficacy of the drug and the usefulness of the ORCs as alternative screening model. Conclusion: ORCs are economical and will be useful for screening new drugs/therapies ex vivo, allowing faster drug screening and thus moving new agents to clinical trials. This work was supported in part by the ELKUS foundation. (*Equal contributing first coauthors)

Citation Format: Sanjib Nilam Banerjee, Prachi Bajpai, Amr Elkholy, Dianne W. Moore, Hyung Gyoon Kim, Sumit Agarwal, Michael Behring, Sameer Al Diffalha, Upender Manne. Development of 3D organoid raft cultures of colon cancer as a model to screen the therapeutic efficacy of PRIMA-1Met (APR-246) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB249.

Abstract LB245: TRIM29 mediates metastasis though hypoxia-regulated proteins in microsatellite-stable and p53-mutated colorectal cancers

In the USA, colorectal cancer (CRC) is a leading cause of cancer deaths in men and women. Two primary molecular subtypes of CRCs are those with microsatellite instability (MSI) and those that are microsatellite stable (MSS). MSI-CRCs have a dysfunction of the mismatch repair (MMR) genes and are less aggressive; MSS-CRCs have active mismatch repair genes, account for 85% of sporadic CRCs, and are more aggressive. CRCs with MSI have a favorable prognosis and are candidates for immunotherapy; those with MSS have a poor prognosis and are resistant to various therapies. Our previous gene expression profiling studies of CRCs showed an association of high expression of tripartite motif-containing 29 (TRIM29) with MSS and p53 mutations. TRIM29, also known as ataxia telangiectasia group D-complementing (ATDC) protein, binds to p53 and inhibits its function. Since point mutations of p53 occur in 50% of CRCs and are associated with the MSS phenotype and with aggressiveness of CRCs, we assessed TRIM29 expression in CRC cells exhibiting various microsatellite and p53 status. With RNA sequencing and qPCR validation, we found higher expression of TRIM29 in MSS and p53-mutated types of CRC cells (HT29 and SW480) as compared to cells exhibiting MSI and the p53 wild-type (HCT116, LOVO, RKO and LS174T) as well as cells with MSS and the p53 wild-type (T84). TRIM29 knockdown studies with HT29 and SW480 CRC cells showed that TRIM29 contributes to the aggressive progression of cells with MSS and p53 mutations. Preclinical studies with experimental animals demonstrated that MSS and p53-mutated CRC cells (HT29) with high expression of TRIM29 metastasized more extensively to liver and bone relative to cells with stably inhibited TRIM29. Further, gene expression profiling of stably inhibited TRIM29 cells showed downregulation of P4HA1, ALDOC, and hexokinase2, enzymes that are involved in the hypoxia pathway. In summary, the present studies show that overexpression of TRIM29 contributes to CRC proliferation, invasion, migration, tumor growth, and experimental metastasis. Thus, targeting of TRIM29 with small molecule inhibitors could be an effective strategy for treatment of CRCs with MSS and p53 mutations. This work was supported in part by an NIH grant (3U54CA118948) and by a grant from the ELKUS foundation.

Citation Format: Sumit Agarwal, Michael Behring, Prachi Bajpai, Amr Elkohly, Hyung-Gyoon Kim, Darshan S. Chandrashekar, Nirzari Gupta, Sameer Al Diffalha, Sooryanarayana Varambally, Upender Manne. TRIM29 mediates metastasis though hypoxia-regulated proteins in microsatellite-stable and p53-mutated colorectal cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB245.

Practical consensus recommendations on Her2 +ve breast cancer with solitary brain mets

Breast cancer is a common cause of brain metastases, with metastases occurring in at least 10-16% of patients. Longer survival of patients with metastatic breast cancer and the use of better imaging techniques are associated with an increased incidence of brain metastases. Current therapies include surgery, whole-brain radiation therapy, stereotactic radiosurgery, chemotherapy and targeted therapies. However, the timing and appropriate use of these therapies is controversial and careful patient selection by using available prognostic tools is extremely important. Expert oncologist discussed on the mode of treatment to extend the OS and improve the quality of life ofHER2-positivebreast cancer patients with Solitary brain metastases. This expert group used data from published literature, practical experience and opinion of a large group of academic oncologists to arrive at this practical consensus recommendations for the benefit of community oncologists.

TRIP13 promotes metastasis of colorectal cancer regardless of p53 and microsatellite instability status

Overexpression of TRIP13, a member of the AAA-ATPase family, is linked with various cancers, but its role in metastasis is unknown in colorectal cancer (CRC). In the current study, we investigated the role TRIP13 in experimental metastasis and its involvement in regulation of WNT/β-catenin and EGFR signaling pathways. Evaluation of formalin-fixed paraffin-embedded (FFPE) and frozen tissues of adenomas and CRCs, along with their corresponding normal samples, showed that TRIP13 was gradually increased in its phenotypic expression from adenoma to carcinoma and that its overexpression in CRCs was independent of patient's gender, age, race/ethnicity, pathologic stage, and p53 and microsatellite instability (MSI) status. Moreover, liver metastases of CRCs showed TRIP13 overexpression as compared to matched adjacent liver tissues, indicating the biological relevance of TRIP13 in CRC progression and metastasis. TRIP13 knockdown impeded colony formation, invasion, motility, and spheroid-forming capacity of CRC cells irrespective of their p53 and MSI status. Furthermore, xenograft studies demonstrated high expression of TRIP13 contributed to tumor growth and metastasis. Depletion of TRIP13 in CRC cells decreased metastasis and it was independent of the p53 and MSI status. Furthermore, TRIP13 interacted with a tyrosine kinase, FGFR4; this interaction could be essential for activation of the EGFR-AKT pathway. In addition, we demonstrated the involvement of TRIP13 in the Wnt signaling pathway and in the epithelial-mesenchymal transition. Cell-based assays revealed that miR-192 and PNPT1 regulate TRIP13 expression in CRC. Additionally, RNA sequencing of CRC cells with TRIP13 knockdown identified COL6A3, TREM2, SHC3, and KLK7 as downstream targets that may have functional relevance in TRIP13-mediated tumor growth and metastasis. In summary, our results demonstrated that TRIP13 promotes tumor growth and metastasis regardless of p53 and MSI status, and indicated that it is a target for therapy of CRC.

Identification of Prognostic Markers in Cholangiocarcinoma Using Altered DNA Methylation and Gene Expression Profiles

Background

Cholangiocarcinoma (CCA) is a rare disease, but it is amongst the most lethal cancers with a median survival under 1 year. Variations in DNA methylation and gene expression have been extensively studied in other cancers for their role in pathogenesis and disease prognosis, but these studies are very limited in CCA. This study focusses on the identification of DNA methylation and gene expression prognostic biomarkers using multi-omics data of CCA tumors from The Cancer Genome Atlas (TCGA).

Method

We have conducted a genome-wide analysis of differential DNA methylation and gene/miRNA expression using data from 36 CCA tumor and 9 normal samples from TCGA. The impact of DNA methylation in promoters and long-range distal enhancers on the regulation and expression of CCA-associated genes was examined using linear regression. Next, we conducted network analyses on genes which are regulated by DNA methylation as well as by miRNA. Finally, we performed Kaplan–Meier and Cox proportional hazards regression analyses in order to identify the role of selected methylation sites and specific genes and miRNAs in patient survival. We also performed real-time quantitative PCR (qPCR) to confirm the change in gene expression in CCA patients’ tumor and adjacent normal samples.

Results

Altered DNA methylation was observed on 12,259 CpGs across all chromosomes, of which 78% were hypermethylated. We observed a strong negative relationship between promoter hypermethylation and corresponding gene expression in 92% of the CpGs. Differential expression analyses revealed altered expression patterns in 3,305 genes and 101 miRNAs. Finally, we identified 17 differentially methylated promoter CpGs, 72 differentially expressed genes, and two miRNAs that are likely associated with patient survival. Pathway analysis suggested that cell division, bile secretion, amino acid metabolism, PPAR signaling, hippo signaling were highly affected by gene expression and DNA methylation alterations. The qPCR analysis further confirmed that MDK, HNF1B, PACS1, and GLUD1 are differentially expressed in CCA.

Conclusion

Based on the survival analysis, we conclude that DEPDC1, FUT4, MDK, PACS1, PIWIL4 genes, miR-22, miR-551b microRNAs, and cg27362525 and cg26597242 CpGs can strongly support their use as prognostic markers of CCA.

Impact of awareness campaigns on Acute Encephalitis Syndrome in Northern India

Introduction

Acute encephalitis syndrome (AES), is a major public health problem in northern India. To meet with the growing concerns of death and disability outcomes of the disease, the Government launched an ambitious awareness campaign in collaboration with the UNICEF. The campaign known as “dastak” comprised of intersectoral convergence for coordinated preventive activities along with widespread door to door awareness programme and envisaged reducing the morbidity and mortality associated with the disease.

Methods

This is a record based retrospective study conducted in the state of Uttar Pradesh, India. Line list of patients suffering from AES, from the year 2016 to 2019, was used to determine number of cases, deaths, case fatality rate, and age group affected. In addition, the time lag between onset of symptoms and hospital admission as well as duration of hospital stay was also calculated. The data were analysed using Statistical Package for Social Sciences (SPSS) version 24.0.

Results

Analysis of data revealed that, in the year 2016 and 2017, there were 8635 reported cases of AES out of which 1296 patients died of the disease. During this period average CFR was 15%. However, after launch of intersectoral preventive and awareness campaign the total number of AES cases dropped to 5262 (3077 cases in 2018 and 2185 cases in 2019) with 374 deaths and an overall CFR of 7.11% during this period. Children are more commonly affected than adults with average age of AES patients being 10.29 and the most commonly affected age group being 1 to 5 years. After introduction of the campaign there was a decrease in mean (± SD) duration between onset of symptoms and hospital admission from 2.20 (± 1.64) to 1.02 (± 0.41) days. Similarly mean (± SD) duration of hospital stay decreased from 7.64 (± 10.83) to 5.6 (± 6.9) days.

Conclusions

Since the introduction of preventive and awareness campaign there has been a significant reduction in morbidity and mortality associated with AES.

Key messages

Impact assessment of preventive activities and awareness campaign on disease helps in making policy decisions and future plan of action for fight against the Acute encephalitis syndrome. Acute encephalitis syndrome is a major public health problem in northern India and early recognition and treatment significantly affects its outcome.

Abstract 63: Navitoclax (ABT-263) induces apoptosis in colon cancer cells by upregulating caspase 3 through inhibition of Bcl-2 family members

Colorectal cancer (CRC) is the third most common cancer in the United States. Most CRCs in patients receiving therapeutic agents are resistant to apoptotic stimuli. Two protein families, caspase enzymes and B-cell lymphoma-2 (Bcl-2) family proteins are involved in apoptosis. Caspase enzymes promote apoptosis, functioning in a cascade, of which caspase 3 is the pivotal protein. Members of the Bcl-2 family, Bcl-2, Bcl-xL, and Bax, are functionally opposed: Bcl-2 and Bcl-xL inhibit apoptosis, whereas Bax counteracts this effect. Only Bcl-2 family members that have the BH3-domain trigger apoptosis by binding to the pro-survival proteins, thereby neutralizing their functional activity. The approach of “BH-3 mimetics” was utilized for discovery and development of navitoclax (ABT-263), a small-molecule that mimics BH3-only proteins and thus induces apoptosis. Despite advances made in targeted therapy, the mechanism of action of ABT-263 is less studied, particularly for CRCs, which have over-expression of anti-apoptotic proteins, supporting avoidance of cell death, a hallmark of cancer. To identify the cellular mechanism of ABT-263 on apoptosis, we quantified the expression of anti-apoptotic Bcl-2-family members in CRC tumor samples relative to their corresponding controls and found several-fold higher expression of Bcl2, Bcl-xL, and Mcl-1 in the CRC tumor samples. Since ABT-263 is a classical drug for Bcl-2 inhibition, we studied its effect (2.5 µM for 24 hr) on RKO CRC cells, which have high endogenous expression of Bcl-2, by measuring gene expression profiles of Bcl-2 family members by qPCR, along with other proteins involved in apoptosis. ABT-263 treatment resulted in down-regulation of anti-apoptotic modulators, Bcl-2, Bcl-xL, and Bcl-w, by 27%, 29%, and 13%, respectively; these effects were concomitant with two-fold higher expression of caspase 3. Flow cytometry results with Annexin V/PI staining showed that ABT-263 induced apoptosis in RKO cells with 1.59-, 2.59-, and 2.76-fold elevations of early apoptotic, late apoptotic, and necrotic cells. Further, ABT-263 (2.5 µM) lowered cell proliferation by 15% after 24 hr. Similar lower gene expressions of Bcl-2 family members were evident for LS174T CRC cells, which also exhibit high endogenous Bcl-2 expression, when treated with ABT-263. These results highlight a previously unexplored effect of ABT-263-induced apoptosis in CRC cells, by upregulating caspase 3, through inhibition of Bcl-2 family members. These studies were supported by the Richard Elkus, MD, Eminent Scholars Program in Gastro-Intestinal Cancer Research at University of Alabama at Birmingham.

Citation Format: Prachi Bajpai, Amr Elkholy, Sumit Agarwal, Hyung Gyoon Kim, Michael Behring, Upender Manne. Navitoclax (ABT-263) induces apoptosis in colon cancer cells by upregulating caspase 3 through inhibition of Bcl-2 family members [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 63.

Abstract 6103: Absence of Mitsuokella multacida is associated with early onset of colorectal cancer

Colorectal cancer (CRC) is a global burden, with an expected 2.2 million annual cases and 1.1 million deaths by 2030. Nearly 90% of CRC cases occur in people over the age of 50. However, early onset (&lt;50 years) of CRC is increasing in Egypt. Prior studies suggest that alteration in microbiome composition (dysbiosis) disturbs the symbiotic relationship between the colorectum and resident micro-organisms and promotes CRC. We hypothesize that, for Egyptians, microbiome dysbiosis is responsible for early-onset of CRC. We further hypothesize that there is cross-talk between the microbiome, tumor molecular features, and the immune microenvironment. Thus, we investigated the molecular profiling of these patients via integrated transcriptional-microbiome analysis. We assessed the colonic microbiota and the expression of specific host response genes in normal colonic mucosal samples from 8 healthy individuals and samples from 20 Egyptian CRC patients. A retrospective convenience sample design was employed. Colonoscopy was performed on these patients at Alexandria University Hospital, Alexandria, Egypt. Microbiota composition was determined by 16S rRNA amplicon sequencing. A panel of 784 genes involved in tumor, microenvironment, and immune response were used to characterize differential expression across patient groups by the Nanostring method. This panel facilitates the estimation of immune cell abundance for 15 tumor-infiltrating immune cell types. Differential abundance and cross-talk between the relative abundance of microbiota and tumor RNA expression were evaluated using negative binomial model fitting and Wald statistics. One third of our CRC patient population was under 50 years old at the time of diagnosis with CRC, and most were female. Healthy controls were even younger than CRC cases, and most were females. There were differences in relative abundances of bacteria between healthy controls and those with CRCs. Analysis showed a low abundance of Mitsuokella multacida, a short-chain fatty acid (SCFA)-producing bacterium, in CRC patients when compared to healthy individuals. In particular, this trend was evident for older CRC patients (≥ 50 years); of note, this bacterium was absent in younger patients (&lt;50 years) (adj. p-value = 0.01). Further, there was a high abundance of Fusobacterium nucleatum in all CRC patients compared to healthy individuals (adj. p-value = 0.04). In cross-talk analysis for healthy controls, elevated abundance of M. multacida was inversely associated with macrophage abundance (global p-value =0.055).For Egyptian patients, the absence of SCFA-producing multacida in younger patients may be a reason for early onset of CRC. These findings suggest that the oncoprotective effect of Mitsuokella multacida should be further investigated. These studies are supported by the US-Egypt STDF grants (NAS 2000007148 and 144/17) and the Impact funds of University of Alabama at Birmingham.

Citation Format: Amr Elkholy, Michael Behring, Mohammed Mohsen, Prachi Bajpai, Amira Embaby, Doaa Header, Reham Abo Elwafa, Hesham Saeed, Mona Fouad, Waleed Arafat, Upender Manne. Absence of Mitsuokella multacida is associated with early onset of colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6103.

Abstract C044: Inter-ethnic differential gene expression in stage II recurrent colorectal cancers

Inter-ethnic differential gene expression in stage II recurrent colorectal cancers Prachi Bajpai1, Amr Elholy1, Michael Behring1, Dongquan Chen2, 3, Kevin Hale1, Sumit Agrawal1, Hyung-Gyoon Kim1, Trafina Jadhav1, Temegsen Samuel4, Upender Manne1, 3 1Department of Pathology, 2Division of Preventive Medicine, Department of Medicine, University of Alabama at Birmingham (UAB), Birmingham, Alabama, USA, 3O’Neal Comprehensive Cancer Center of UAB, Birmingham; 4Department of Pathobiology, College of Veterinary Medicine, Tuskegee University, Tuskegee, Alabama, USA Background and Objective: For colorectal cancer (CRC), the second most common cause of cancer-related death in the US, there are racial/ethnic disparities in incidence and mortality. Of these patients, 25-35% with pathologic Stage II CRCs exhibit recurrence after surgery with curative intent. Relative to Caucasian (CA) patients, African American (AA) patients with CRC have a 20% higher stage-specific mortality. The present study delineates a distinct gene expression profile, specific for Stage II CRCs, based on disease recurrence and patient race/ethnicity. Methods: We obtained gene expression profiles for Stage II CRCs from 16 AA and 30 CA patients by the use of Affymetrix GeneChip microarrays. Samples from patients with recurrent disease, within 5 years post-surgery, were compared to those with non-recurrent CRCs within 5 years post-surgery. For comparison between AA with CA patients, gene expression was assessed. Results: For recurrent CRCs, there were nine genes common to AA and CA patients, suggesting a common gene signature specific for Stage II disease. For tumors, relative to their corresponding normal tissues, there was higher expression of five of these genes; the direction of association with disease recurrence was distinct with race/ethnicity. GFM2, DCAF17, and GEN1 had a positive association with recurrence in CAs and a negative association with recurrence in AAs. Additionally, for recurrent patients, TAPBP and FEZ were upregulated in AAs and downregulated in CAs (False Discovery Rate &lt;0.05 for all genes). BCL2L2, OXA1L, AHNAK2, and MEGF6 were consistently overexpressed in CRCs of both race/ethnicity groups. Currently, we are validating these findings in a prospective Stage II CRC cohort to correlate observations with time to recurrence. Conclusion: The present study identifies molecular signatures, specific for Stage II CRCs, for patients of two ethnic backgrounds, and contribute to a better understanding of the CRC health disparities for AAs and CA. This work was supported by a NIH/NCI grant (U54CA118948).

Citation Format: Prachi Bajpai, Amr Elholy, Michael Behring, Dongquan Chen, Kevin Hale, Sumit Agrawal, Hyung-Gyoon Kim, Trafina Jadhav, Temegsen Samuel, Upender Manne. Inter-ethnic differential gene expression in stage II recurrent colorectal cancers [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr C044.

Targeting P4HA1 with a Small Molecule Inhibitor in a Colorectal Cancer PDX Model

Deposition, remodeling, and signaling of the extracellular matrix facilitate tumor growth and metastasis. Here, we demonstrated that an enzyme, collagen prolyl 4-hydroxylase, alpha polypeptide I (P4HA1), which is involved in collagen synthesis and deposition, had elevated expression in colorectal cancers (CRCs) as compared to normal colonic tissues. The expression of P4HA1 in CRCs was independent of patient's age, race/ethnicity, gender, pathologic stage and grade, tumor location, and microsatellite instability (MSI) and p53 status. By modulating P4HA1 with shRNA, there was a reduction in malignant phenotypes of CRCs, including cell proliferation, colony formation, invasion, migration, and tumor growth, in mice regardless of their p53 and MSI status. Immunoblot analysis of excised xenograft tumors developed from cells with silenced PH4HA1 showed low levels of proliferating cell nuclear antigen. Further, in CRC mouse models, silencing of P4HA1 in HT29 cells resulted in less metastasis to liver and bone. P4HA1 expression was regulated by miR-124, and inhibition of cell growth was noted for CRC cells treated with miR-124. Furthermore, low levels of the transcriptional repressor EZH2 reduced P4HA1 expression in CRC cells. Inhibition of P4HA1 with the small molecule inhibitor diethyl-pythiDC decreased AGO2 and MMP1, which are P4HA1 target molecules, and reduced the malignant phenotypes of CRC cells. Treatment of CRC patient-derived xenografts that exhibit high expression of P4HA1 with diethyl-pythiDC resulted in tumor regression. Thus, the present study shows that P4HA1 contributes to CRC progression and metastasis and that targeting of P4HA1 with diethyl-pythiDC could be an effective therapeutic strategy for aggressive CRCs.

Mitochondrial localization, import, and mitochondrial function of the androgen receptor

Nuclear localization of androgen receptor (AR) directs transcriptional regulation of a host of genes, referred to as genomic signaling. Additionally, nonnuclear or nongenomic activities of the AR have long been described, but understanding of these activities remains elusive. Here, we report that AR is imported into and localizes to mitochondria and has a novel role in regulating multiple mitochondrial processes. Employing complementary experimental approaches of AR knockdown in AR-expressing cells and ectopic AR expression in AR-deficient cells, we demonstrate an inverse relationship between AR expression and mitochondrial DNA (mtDNA) content and transcription factor A, mitochondrial (TFAM), a regulator of mtDNA content. We show that AR localizes to mitochondria in prostate tissues and cell lines and is imported into mitochondria in vitro We also found that AR contains a 36-amino-acid-long mitochondrial localization sequence (MLS) capable of targeting a passenger protein (GFP) to the mitochondria and that deletion of the MLS abolishes the import of AR into the mitochondria. Ectopic AR expression reduced the expression of oxidative phosphorylation (OXPHOS) subunits. Interestingly, AR also controlled translation of mtDNA-encoded genes by regulating expression of multiple nuclear DNA-encoded mitochondrial ribosomal proteins. Consistent with these observations, OXPHOS supercomplexes were destabilized, and OXPHOS enzymatic activities were reduced in AR-expressing cells and restored upon AR knockdown. Moreover, mitochondrial impairment induced AR expression and increased its translocation into mitochondria. We conclude that AR localizes to mitochondria, where it controls multiple mitochondrial functions and mitonuclear communication. Our studies also suggest that mitochondria are novel players in nongenomic activities of AR.

Epigenetic modification of miR-663 controls mitochondria-to-nucleus retrograde signaling and tumor progression

The normal cellular function requires communication between mitochondria and the nucleus, termed mitochondria-to-nucleus retrograde signaling. Disruption of this mechanism has been implicated in the development of cancers. Many proteins are known modulators of retrograde signaling, but whether microRNAs (miRNAs) are also involved is unknown. We conducted an miRNA microarray analysis using RNA from a parental cell line, a Rho⁰ line lacking mitochondrial DNA (mtDNA) and a Rho⁰ line with restored mtDNA. We found that miR-663 was down-regulated in the mtDNA-depleted Rho⁰ line. mtDNA restoration reversed this miRNA to parental level, suggesting that miR-663 may be epigenetically regulated by retrograde signaling. By using methylation-specific PCR and bisulfite sequencing we demonstrate that miR-663 promoter is epigenetically regulated not only by genetic but also by pharmacological disruption of oxidative phosphorylation (OXPHOS). Restoration of OXPHOS Complex I inhibitor-induced miR-663 expression by N-acetylcysteine suggested that reactive oxygen species (ROS) play a key role in epigenetic regulation of miR-663. We determined that miR-663 regulates the expression of nuclear-encoded respiratory chain subunits involved in Complexes I, II, III, and IV. miR-663 also controlled the expression of the Complexes I (NDUFAF1), II (SDHAF2), III (UQCC2), and IV (SCO1) assembly factors and was required for stability of respiratory supercomplexes. Furthermore, using luciferase assays, we found that miR-663 directly regulates UQCC2. The anti-miR-663 reduced OXPHOS complex activity and increased in vitro cellular proliferation and promoted tumor development in vivo in mice. We also found that increased miR-663 expression in breast tumors consistently correlates with increased patient survival. We provide the first evidence for miRNA controlling retrograde signaling, demonstrating its epigenetic regulation and its role in breast tumorigenesis.

Abstract 1494: Interethnic germline variants in mitochondrial DNA polymerase (POLG1) induce mitochondrial dysfunction and confer tumorigenic properties

Purpose: Germline variants contribute to large fraction of the diversity observed among different ethnic groups and could give better insights in genetic predisposition and susceptibility from one population to another for certain disease including cancer. Decreased mitochondrial OXPHOS is one of the most common phenotypes of cancer cells. Mitochondrial DNA (mtDNA) depletion impairs OXPHOS and adaptive metabolic responses. In this context, DNA polymerase γ (POLG1) is known to function in human mitochondria and performs critical function of mtDNA replication and repair. POLG1 is the most frequent target of gene mutation and is involved in variety of mitochondrial diseases. POLG1 protein consists of exonuclease, linker and polymerase domain, each with distinct functions. Mutations in exonuclease domain leads to erroneous proofreading and is responsible for increased mutations in mtDNA whereas mutations in polymerase domain leads to erroneous replication and hence depletion in mtDNA. Germline variants in these domains of POLG1 may serve as important signature markers in association studies of individuals in a population study. Through our present study, we identified germline variants, examined copy number variation, expression and regulation of POLG1 gene in human cancers. We provide evidence that altered POLG1 expression as well as germline variations in POLG1 gene contribute to tumorigenesis.

Methods: A comprehensive race based bioinformatics analysis of POLG1 gene in European-American and African-American was conducted and several unique germline mutations were discovered. To analyze functional contribution of these unique germline mutations in tumor progression, these unique prevalent mutations in the evolutionary conserved regions of exonuclease and polymerase domains we generated by site directed mutagenesis and functional and tumorigenic analysis was performed.

Results: We observed marked differences in copy number variation of POLG1 through cBioPortal and Cosmic databases and validated the analysis in primary tumors and cancer cell lines. Our results also indicate that mtDNA copy number in cancer cell is governed by regulation of POLG1 methylation and demethylation status, suggestive of epigenetic regulation of POLG1. We identified a mitochondrial disease causing missense variation in polymerase domain of POLG1 at amino acid 1143 (E1143G) to be 25 times more prevalent in European-Americans when compared to African-Americans population. Expression of this germline variant (E1143G) increased glucose consumption, decreased ATP production and increased matrigel invasion.

Discussion/ Conclusion: We demonstrate that POLG1 is epigenetically regulated and its unique germline variants contribute to disruption of mitochondrial function. Thus contributes to differences in increased predisposition to cancer in inter-ethnic population.

Note: This abstract was not presented at the meeting.

Citation Format: Prachi Bajpai, Bhupendra Singh, Kjerstin M. Owens, Vinodh Srinivasasainagendra, Hemant K. Tiwari, Keshav K. Singh. Interethnic germline variants in mitochondrial DNA polymerase (POLG1) induce mitochondrial dysfunction and confer tumorigenic properties [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1494. doi:10.1158/1538-7445.AM2017-1494

Migration of mitochondrial DNA in the nuclear genome of colorectal adenocarcinoma

Background

Colorectal adenocarcinomas are characterized by abnormal mitochondrial DNA (mtDNA) copy number and genomic instability, but a molecular interaction between mitochondrial and nuclear genome remains unknown. Here we report the discovery of increased copies of nuclear mtDNA (NUMT) in colorectal adenocarcinomas, which supports link between mtDNA and genomic instability in the nucleus. We name this phenomenon of nuclear occurrence of mitochondrial component as numtogenesis. We provide a description of NUMT abundance and distribution in tumor versus matched blood-derived normal genomes.

Methods

Whole-genome sequence data were obtained for colon adenocarcinoma and rectum adenocarcinoma patients participating in The Cancer Genome Atlas, via the Cancer Genomics Hub, using the GeneTorrent file acquisition tool. Data were analyzed to determine NUMT proportion and distribution on a genome-wide scale. A NUMT suppressor gene was identified by comparing numtogenesis in other organisms.

Results

Our study reveals that colorectal adenocarcinoma genomes, on average, contains up to 4.2-fold more somatic NUMTs than matched normal genomes. Women colorectal tumors contained more NUMT than men. NUMT abundance in tumor predicted parallel abundance in blood. NUMT abundance positively correlated with GC content and gene density. Increased numtogenesis was observed with higher mortality. We identified YME1L1, a human homolog of yeast YME1 (yeast mitochondrial DNA escape 1) to be frequently mutated in colorectal tumors. YME1L1 was also mutated in tumors derived from other tissues. We show that inactivation of YME1L1 results in increased transfer of mtDNA in the nuclear genome.

Conclusions

Our study demonstrates increased somatic transfer of mtDNA in colorectal tumors. Our study also reveals sex-based differences in frequency of NUMT occurrence and that NUMT in blood reflects NUMT in tumors, suggesting NUMT may be used as a biomarker for tumorigenesis. We identify YME1L1 as the first NUMT suppressor gene in human and demonstrate that inactivation of YME1L1 induces migration of mtDNA to the nuclear genome. Our study reveals that numtogenesis plays an important role in the development of cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s13073-017-0420-6) contains supplementary material, which is available to authorized users.

HLA-B27 subtypes in enthesitis-related arthritis category of juvenile idiopathic arthritis and ankylosing spondylitis in northern India

OBJECTIVES

Enthesitis-related arthritis (ERA) is the most common form of juvenile idiopathic arthritis (JIA) in the Asian and Indian populations. The presence of HLA-B27 has a strong association with JIA-ERA similar to that with adult ankylosing spondylitis (AS). The HLA-B27gene is highly polymorphic. Susceptibility to AS varies between different HLA-B27 subtypes; data on the relationship of susceptibility to JIA-ERA with HLA-B27 types are scant. In this study, we determined HLA-B27 subtypes in patients with JIA-ERA and AS to find out whether there is any difference in the HLA-B27 subtypes prevalent in these two diseases.

METHODS

Genomic DNA from 135 patients with JIA-ERA and 121 with AS was tested for the presence of HLA-B27. In patients testing positive, HLA-B27subtyping was done by sequencing a genomic region that contained second and third exons and the intervening intron of this gene; this method permitted identification of common HLA-B27 subtypes (HLA-B*27:01 to HLA-B*27:09).

RESULTS

One hundred and seven (79%) patients with JIA-ERA and 102 (84%) patients with AS tested positive for HLA-B27. In both groups, HLA-B*27:05 and HLA-B*27:04 were the common subtypes; some patients had HLA-B*27:07(7.4%) and HLA-B*27:18. Patients with JIA-ERA had a higher frequency of HLA-B*27:05 than those with AS (70% vs. 57%, p=0.047), and a lower frequency of HLA-B*27:04 (21% vs. 36%, p=0.018).

CONCLUSIONS

HLA-B*27:05 and HLA-B*27:04 were the most common HLA-27 subtypes in both JIA-ERA and AS. However, HLA-B*27:05 was more frequent and HLA-B*27:04 was less frequent in JIA-ERA. It is possible that HLA-B*27:05 being the ancestral HLA-27 subtype leads to expression of disease early in life.

Mitochondrial DNA Polymerase POLG1 Disease Mutations and Germline Variants Promote Tumorigenic Properties

Germline mutations in mitochondrial DNA polymerase gamma (POLG1) induce mitochondrial DNA (mtDNA) mutations, depletion, and decrease oxidative phosphorylation. Earlier, we identified somatic mutations in POLG1 and the contribution of these mutations in human cancer. However, a role for germline variations in POLG1 in human cancers is unknown. In this study, we examined a role for disease associated germline variants of POLG1, POLG1 gene expression, copy number variation and regulation in human cancers. We analyzed the mutations, expression and copy number variation in POLG1 in several cancer databases and validated the analyses in primary breast tumors and breast cancer cell lines. We discovered 5-aza-2'-deoxycytidine led epigenetic regulation of POLG1, mtDNA-encoded genes and increased mitochondrial respiration. We conducted comprehensive race based bioinformatics analyses of POLG1 gene in more than 33,000 European-Americans and 5,000 African-Americans. We identified a mitochondrial disease causing missense variation in polymerase domain of POLG1 protein at amino acid 1143 (E1143G) to be 25 times more prevalent in European-Americans (allele frequency 0.03777) when compared to African-American (allele frequency 0.00151) population. We identified T251I and P587L missense variations in exonuclease and linker region of POLG1 also to be more prevalent in European-Americans. Expression of these variants increased glucose consumption, decreased ATP production and increased matrigel invasion. Interestingly, conditional expression of these variants revealed that matrigel invasion properties conferred by these germline variants were reversible suggesting a role of epigenetic regulators. Indeed, we identified a set of miRNA whose expression was reversible after variant expression was turned off. Together, our studies demonstrate altered genetic and epigenetic regulation of POLG1 in human cancers and suggest a role for POLG1 germline variants in promoting tumorigenic properties.

Targeting of splice variants of human cytochrome P450 2C8 (CYP2C8) to mitochondria and their role in arachidonic acid metabolism and respiratory dysfunction

In this study, we found that the full-length CYP2C8 (WT CYP2C8) and N-terminal truncated splice variant 3 (∼ 44-kDa mass) are localized in mitochondria in addition to the endoplasmic reticulum. Analysis of human livers showed that the mitochondrial levels of these two forms varied markedly. Molecular modeling based on the x-ray crystal structure coordinates of CYP2D6 and CYP2C8 showed that despite lacking the N-terminal 102 residues variant 3 possessed nearly complete substrate binding and heme binding pockets. Stable expression of cDNAs in HepG2 cells showed that the WT protein is mostly targeted to the endoplasmic reticulum and at low levels to mitochondria, whereas variant 3 is primarily targeted to mitochondria and at low levels to the endoplasmic reticulum. Enzyme reconstitution experiments showed that both microsomal and mitochondrial WT CYP2C8 efficiently catalyzed paclitaxel 6-hydroxylation. However, mitochondrial variant 3 was unable to catalyze this reaction possibly because of its inability to stabilize the large 854-Da substrate. Conversely, mitochondrial variant 3 catalyzed the metabolism of arachidonic acid into 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids and 20-hydroxyeicosatetraenoic acid when reconstituted with adrenodoxin and adrenodoxin reductase. HepG2 cells stably expressing variant 3 generated higher levels of reactive oxygen species and showed a higher level of mitochondrial respiratory dysfunction. This study suggests that mitochondrially targeted variant 3 CYP2C8 may contribute to oxidative stress in various tissues.

Metabolism of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine by mitochondrion-targeted cytochrome P450 2D6: implications in Parkinson disease

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxic side product formed in the chemical synthesis of desmethylprodine opioid analgesic, which induces Parkinson disease. Monoamine oxidase B, present in the mitochondrial outer membrane of glial cells, catalyzes the oxidation of MPTP to the toxic 1-methyl-4-phenylpyridinium ion (MPP(+)), which then targets the dopaminergic neurons causing neuronal death. Here, we demonstrate that mitochondrion-targeted human cytochrome P450 2D6 (CYP2D6), supported by mitochondrial adrenodoxin and adrenodoxin reductase, can efficiently catalyze the metabolism of MPTP to MPP(+), as shown with purified enzymes and also in cells expressing mitochondrial CYP2D6. Neuro-2A cells stably expressing predominantly mitochondrion-targeted CYP2D6 were more sensitive to MPTP-mediated mitochondrial respiratory dysfunction and complex I inhibition than cells expressing predominantly endoplasmic reticulum-targeted CYP2D6. Mitochondrial CYP2D6 expressing Neuro-2A cells produced higher levels of reactive oxygen species and showed abnormal mitochondrial structures. MPTP treatment also induced mitochondrial translocation of an autophagic marker, Parkin, and a mitochondrial fission marker, Drp1, in differentiated neurons expressing mitochondrial CYP2D6. MPTP-mediated toxicity in primary dopaminergic neurons was attenuated by CYP2D6 inhibitor, quinidine, and also partly by monoamine oxidase B inhibitors deprenyl and pargyline. These studies show for the first time that dopaminergic neurons expressing mitochondrial CYP2D6 are fully capable of activating the pro-neurotoxin MPTP and inducing neuronal damage, which is effectively prevented by the CYP2D6 inhibitor quinidine.

Continuous ethanol production from Jerusalem artichoke tubers. II. Use of immobilized cells of Kluyveromyces marxianus

Kluyveromyces marxianus UCD (FST) 55-82 cells were immobilized in Na alginate beads and used in a packed-bed bioreactor system for the continuous production of ethanol from the extract of Jerusalem artichoke tubers. Volumetric ethanol productivities of 104 and 80 g ethanol/ L/h were obtained at 80 and 92% sugar utilization, respectively. The maximum volumetric ethanol productivity of the immobilized cell bioreactor system was found to be 15 times higher than that of an ordinary-stirred-tank (CST) bioreactor using cells of K. marxianus. The immobilized cell bioreactor system was operated continuously at a constant dilution rate of 0.66 h(-1) for 12 days resulting in only an 8% loss of the original immobilized cell activity, which corresponds to an estimated half-life of ca. 72 days. The maximum specific ethanol productivity and maximum specific sugar uptake rate of the immobilized cells were found to be 0.55 g ethanol/g/biomass/h and 1.21 g sugars/g biomass/h, respectively.

Continuous ethanol production from Jerusalem artichoke tubers. I. Use of free cells of Kluyveromyces marxianus

The Continuous fermentation of Jerusalem artichoke juice to ethanol by free cells of Kluyveromyces marxianus UCD (FST) 55-82 has been studied in a continuous-stirred-tank bioreactor at 35 degrees C and pH 4.6. A maximum yield of 90% of the theoretical was obtained at a dilution rate of 0.05 h(-1). About 95% of the sugars were utilized at dilution rates lower than 0.15 h(-1). Volumetric ethanol productivity and volumetric biomass productivity reached maximum values of 7 g ETOH/L/h and 0.6 g dry wt/L/h, respectively, at a dilution rate of 0.2 h(-1). The maintenance energy coefficient for K. marxianus culture was found to be 0.46 g sugar/g biomass/h/ Oscillatory behavior was following a change in dilution rate from a previous steady state and from batch to continuous culture. Values of specific ethanol production rate and specific sugar uptake were found to increase almost linearly with the increase of the dilution rate. The maximum specific ethanol production rate and maximum specific sugar uptake rate were found to be 2.6 g ethanol/g/ cell/h and 7.9 sugars/g cell/h, respectively. Washout occurred at a dilution rate of 0.41 h(-1).

The effect of temperature and pH on ethanol production by free and immobilized cells of Kluyveromyces marxianus grown on Jerusalem artichoke extract

The effect of temperature and pH on the kinetics of ethanol production by free and calcium alginate immobilized cells of Kluyveromyces marxianus grown on Jerusalem artichoke extract was investigated. With the free cells, the ethanol and biomass yields were relatively constant over the temperature range 25-35 degrees C, but dropped sharply beyond 35 degrees C. Other kinetic parameters, specific growth rate, specific ethanol production rate, and specific total sugar uptake rate were maximum at 35 degrees C. However, with the immobilized cells, ethanol yield remained almost constant in the temperature range 25-45 degrees C, and the specific ethanol production rate and specific total sugar uptake rate attained their maximum values at 40 degrees C. For the pH range between 3 and 7, the free-cell optimum for growth and product formation was found to be ca. pH 5. At this pH, the specific growth rate was 0.35 h(-1) and specific ethanol production rate was 2.83 g/g/h. At values higher or lower than pH 5, a sharp decrease in specific ethanol production rate as well as specific growth rate was observed. In comparison, the immobilized cells showed a broad optimum pH profile. The best ethanol production rates were observed between pH 4 and 6.

Bimodal targeting of cytochrome P450s to endoplasmic reticulum and mitochondria: the concept of chimeric signals

Targeting signals are critical for proteins to find their specific cellular destination. Signals for protein targeting to the endoplasmic reticulum (ER), mitochondria, peroxisome and nucleus are distinct and the mechanisms of protein translocation across these membrane compartments also vary markedly. Recently, however, a number of proteins have been shown to be present in multiple cellular sites such as mitochondria and ER, cytosol and mitochondria, plasma membrane and mitochondria, and peroxisome and mitochondria suggesting the occurrence of multimodal targeting signals in some cases. Cytochrome P450 monooxygenases (CYPs), which play crucial roles in pharmacokinetics and pharmacodynamics of drugs and toxins, are the prototype of bimodally targeted proteins. Several members of family 1, 2 and 3 CYPs have now been reported to be associated with mitochondria and plasma membrane in addition to the ER. This review highlights the mechanisms of bimodal targeting of CYP1A1, 2B1, 2E1 and 2D6 to mitochondria and ER. The bimodal targeting of these proteins is driven by their N-terminal signals which carry essential elements of both ER targeting and mitochondria targeting signals. These multimodal signals have been termed chimeric signals appropriately to describe their dual targeting property. The cryptic mitochondrial targeting signals of CYP2B1, 2D6, 2E1 require activation by protein kinase A or protein kinase C mediated phosphorylation at sites immediately flanking the targeting signal and/or membrane anchoring regions. The cryptic mitochondria targeting signal of CYP1A1 requires activation by endoproteolytic cleavage by a cytosolic endoprotease, which exposes the mitochondrial signal. This review discusses both mechanisms of bimodal targeting and toxicological consequences of mitochondria targeted CYP proteins.

Arachidonic Acid production by fungi

After preliminary screening, Mortierella alpina and Mortierella elongata were compared with respect to arachidonic acid content. M. alpina ATCC 16266 produced 2.1 g of arachidonic acid per liter in media containing 10% glucose while the highest percentage of arachidonic acid in lipid (43.3%) was observed at a glucose concentration of 2%. Arachidonic acid content in lipids increased to 66% during storage.

Ethanol Inhibition Kinetics of Kluyveromyces marxianus Grown on Jerusalem Artichoke Juice

The kinetics of ethanol inhibition on cell growth and ethanol production by Kluyveromyces marxianus UCD (FST) 55-82 were studied during batch growth. The liquid medium contained 10% (wt/vol) inulin-type sugars derived from an extract of Jerusalem artichoke (Helianthus tuberosus) tubers, supplemented with small amounts of Tween 80, oleic acid, and corn steep liquor. Initial ethanol concentrations ranging from 0 to 80 g/liter in the liquid medium were used to study the inhibitory effect of ethanol on the following parameters: maximum specific growth rate (mu(max)), cell and ethanol yields, and sugar utilization. It was found that as the initial ethanol concentration increased from 0 to 80 g/liter, and maximum specific growth rate of K. marxianus cells decreased from 0.42 to 0.09 h, whereas the ethanol and cell yields and sugar utilization remained almost constant. A simple kinetic model was used to correlate the mu(max) results and the rates of cell and ethanol production, and the appropriate constants were evaluated.

Direct Fermentation of d-Xylose to Ethanol by Kluyveromyces marxianus Strains

Eight strains of Kluyveromyces marxianus were screened, and all of them were found to ferment the aldopentose d-xylose directly to ethanol under aerobic conditions. One of these strains, K. marxianus SUB-80-S, was grown in a medium containing 20 g of d-xylose per liter, and the following results were obtained: maximum ethanol concentration, 5.6 g/liter; ethanol yield, 0.28 g of ethanol per g of d-xylose (55% of theoretical); maximum specific growth rate, 0.12 h; 100% d-xylose utilization was completed in 48 h.

Effect of Sugar Concentration in Jerusalem Artichoke Extract on Kluyveromyces marxianus Growth and Ethanol Production

The effect of inulin sugars concentration on the growth and ethanol production by Kluyveromyces marxianus UCD (FST) 55-82 was studied. A maximum ethanol concentration of 102 g/liter was obtained from 250 g of sugars per liter initial concentration. The maximum specific growth rate varied from 0.44 h at 50 g of sugar per liter to 0.13 h at 300 g of sugar per liter, whereas the ethanol yield remained almost constant at 0.45 g of ethanol per g of sugars utilized.

Ethanol production from Jerusalem artichoke tubers (Helianthus tuberosus) using Kluyveromyces marxianus and Saccharomyces rosei

This article examines the potential of Jerusalem artichoke as a source for ethanol and single-cell protein SCP. In addition, experimental results are presented on batch fermentation kinetics employing two strains of Kluyveromyces marxianus and one strain of Saccharomyces rosei grown on the extract derived from the tubers of Jerusalem artichoke. Of the three cultures examined, Kluyveromyces marxianus UCD (FST) 55-82 was found to be the best producer of ethanol grown in a simple medium at 35 degrees C. The ethanol production was found to be growth-associated having a mu(max) = 0.41. h(-1) and the ethanol and biomass yields were determined to be Y(p/s) = 0.45 (88% of the theoretical) and Y(x/s) = 0.04 with 92% of the original sugars utilized. On the basis of carbohydrate yields of Jerusalem artichoke reported in the literature and these batch kinetic studies with K. maxxianus, the calculated ethanol yields were found to range from 1400 kg ethanol acre (-1) yr(-1)to a maximum of 2700 kg ethanol acre (-1) yr(-1). The SCP yields for K. marxianus were calculated to range between 130 to 250 kg dry wt cell acre (-1) yr(-1). The potential for developing an integrated process to produce ethanol and SCP is also discussed.

Genetic polymorphism of CYP3A5 in Indian chronic myeloid leukemia patients

CYP3A5 is an important genetic contributor to inter-individual differences in CYP3A-dependent clinically important drugs of metabolism and also of various endogenous compounds and environmental contaminants. The CYP3A5*3 allele results in a truncated protein with loss of CYP3A5 expression and CYP3A5*6 is associated with lower CYP3A5 catalytic activity. The polymorphism analysis was performed by PCR-RFLP and some representative cases by direct sequencing. Our case control study involved 183 consecutive North Indian CML patients in chronic phase of disease and 208 geographically and racially matched healthy controls. PCR-RFLP was carried out to determine the frequency of CYP3A5*3 and CYP3A5*6 genotypes. The relationship between these allelic variants and risk of CML was assessed by means of odds ratio (OR) with 95% confidence limits calculated by logistic regression. The frequencies of CYP3A5*1/*1, CYP3A5*1/*3, and CYP3A5*3/*3 genotypes in CML and controls were examined, and the quantitative comparison of the frequency distributions between CML versus control were performed, showing no significant differences among these comparison pairs (P = 0.88, 0.65, and 0.80, respectively). However, we did not find the CYP3A5*6 allele in any of the controls and leukemia patients. It is concluded that there is no association of this polymorphism with the risk of chronic myeloid leukemia.

Abstract B42: Polymorphism of CYP3A5 gene in Indian chronic myeloid leukemia patients

B42

Objective

Chronic myeloid leukemia (CML) is a clonal hematopoetic stem cell disorder characterized by the Philadelphia chromosome. Individuals vary in their ability to metabolize carcinogens and hence to detoxify chemicals, leading to different risk in getting cancer. The human CYP3A5 is a major P450 enzyme in the liver and represents 50% of the total hepatic CYP3A content in people expressing CYP3A5. Therefore, it is suggested that the CYP3A5 is an important genetic contributor to inter-individual differences in CYP3A-dependent drug metabolism. Owing to the importance of CYP3A5 genetic polymorphism as risk factor in various cancers, the study was aimed to detect the prevalence of genetic polymorphism of CYP3A5*3 gene in North Indian CML patients and racially matched controls. Further, it will help to determine the association of these allelic variants if any, as risk factor to develop CML.

Materials and Methods

Human blood was collected from 50 CML patients and 65 healthy individuals which were age and sex matched. DNA isolation was carried out by standard proteinase K and phenol chloroform method. The prevalence of CYP3A5*3 genotype was examined by PCR-RFLP method. PCR products were separated using 2% agarose gel.

In the analysis of the CYP3A5*3 polymorphism, a fragment of 155 base pairs (bp) was amplified by PCR, which was followed by restriction digestion by Dde I. The 155 bp product from the CYP3A5*1 allele was digested into 121 and 34 bp fragments, whereas the PCR product of the CYP3A5*3 was cleaved to 97, 34, and 24 bp fragments.

Results

The frequencies reported in controls were, 7/65 (10.76%) for homozygous CYP3A5*1/*1 , 28/65 (43.07%) for heterozygous CYP3A5*1/*3 and was 30/65 (46.15%) for homozygous CYP3A5*3/*3 respectively. The frequencies reported in cases were 5/50 (10%), 21/50 (42%) and 24/50 (48%) respectively. There was no significant difference between the frequencies of wild (*1/*1), heterozygous (*1/*3) & mutant allele (*3/*3), (control vs cases).

However, when these alleles where compared individually within a class, a higher frequency of

heterozygous & mutant allele, was reported as compared to the wild type, both in the cases and in controls. The combined frequency of heterozygous & mutant allele vs wild in controls was 89.22% and 10.76% respectively, and that in cases being 90% and 10% respectively.

Discussion

It is concluded that there is no association of this polymorphism with the risk of Chronic Myeloid Leukemia. However, due to the variable frequencies of xenobiotic metabolizing polymorphic alleles in different populations, further studies with different populations are required in order to investigate the association of polymorphic variability and its possible role in susceptibility to CML.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):B42.

Increased frequencies of glutathione-S-transferase (GSTM1 and GSTT1) null genotypes in Indian patients with chronic myeloid leukemia

Inherited differences in the capacity of xenobiotic metabolizing enzymes might be an important factor in genetic susceptibility to cancer. Null genotypes of glutathione-S-transferases (GSTs) exhibit absence of enzymatic activity and are hypothesized to be at increased risk of developing cancers. The aim of the study was to examine whether null genotypes of GSTM1 and GSTT1 confer susceptibility to chronic myeloid leukemia (CML). We carried a case control study involving 80 consecutive North Indian CML patients (58 males, 22 females; age (mean+/-S.D.) 36.2+/-10.9 years) and 105 healthy individuals (59 males, 46 females; age (mean+/-S.D.) 36.8+/-11.3 years). Multiplex PCR was carried out to determine the frequency of GSTM1 and GSTT1 null genotypes. The relationship between GSTM1, GSTT1 genotypes and risk of CML was assessed by means of odds ratio (OR) with 95% confidence limits calculated by logistic regression. A test for trend (P(trend)) in increasing the risk of CML having more than one putative high-risk allele or genotype was evaluated by means of the chi-square test. There was no difference in the frequencies of the GSTM1 null genotype and the combined GSTM1 and GSTT1 null genotypes between patients and controls in the study. However, statistical significance was found with GSTT1 null genotype frequency in CML patients as compared to controls (16/80 (20%) versus 9/105 (8.5%); OR=2.67, 95% CI: 1.03-7.01). It projects a 2.67-fold increased risk for CML in individuals with GSTT1 null genotype as compared to those possessing both alleles of the gene. Our findings suggest that heritable GST status may influence the risk of developing CML.

Macrophages in the development of protective immunity against experimental Brugia malayi infection

The present report compares the macrophage function in rodent hosts susceptible and resistant to the human lymphatic filariid Brugia malayi. Macrophages from both mastomys (resistant) and gerbil (susceptible) infected intraperitoneally (i.p.) with the infective larvae (L3) of B. malayi were isolated from peritoneal lavage at different time-intervals and formation rate of NO, H2O2, O2-, TNF-alpha, glutathione peroxidase and reductase was assayed. NO release was found to be significantly increased in resistant mastomys as compared to gerbils and the release was markedly suppressed by i.p. administration of the NOS inhibitor aminoguanidine (AG). The AG-treated mastomys also demonstrated significantly greater establishment of larvae which correlated well with suppressed formation of NO. Nitric oxide synergizes with superoxide to form peroxynitrite radical (potent oxidant), which is known to be more toxic per se than NO. Results indicate the possible involvement of peroxynitrite in the rapid killing of larvae in the peritoneal cavity of mastomys. In contrast, the production of H2O2 was found to be enhanced in both species indicating that B. malayi L3 could withstand the toxic effects of H2O2. The higher level of glutathione peroxidase and reductase, as observed in mastomys compared with the gerbil after larval introduction, possibly protects the cell against the injurious effect of H2O2. The TNF-alpha level remained virtually unchanged in both the hosts, suggesting an insignificant role for this cytokine in parasite establishment.

Decolorization and detoxification of extraction-stage effluent from chlorine bleaching of kraft pulp by Rhizopus oryzae

Rhizopus oryzae, a zygomycete, was found to decolorize, dechlorinate, and detoxify bleach plant effluent at lower cosubstrate concentrations than the basidiomycetes previously investigated. With glucose at 1 g/liter, this fungus removed 92 to 95% of the color, 50% of the chemical oxygen demand, 72% of the adsorbable organic halide, and 37% of the extractable organic halide in 24 h at temperatures of 25 to 45 degrees C and a pH of 3 to 5. Even without added cosubstrate the fungus removed up to 78% of the color. Monomeric chlorinated aromatic compounds were removed almost completely, and toxicity to zebra fish was eliminated. The fungal mycelium could be immobilized in polyurethane foam and used repeatedly to treat batches of effluent. The residue after treatment was not further improved by exposure to fresh R. oryzae mycelium.

One year histopathological evaluation of fibrous tissue surrounding TCPL implants using adult rats as a model

Fibrous tissue formation is often used as a screening method to determine the biocompatibility of orthopaedic and dental implanted material. In this investigation, porous implants of tricalcium phosphate-lysine delivery devices were implanted intraperitoneally (IP) using adult male rats as a model. The fibrous tissue surrounding the implant was studied histologically to determine the infiltration of inflammatory cells and other healing components. Fibrous capsular tissues were carefully dissected away from the capsule noting the tissue closest to the implanted material. Evaluation of the sections (5um, H&E) collected from various areas of the implants (n = 5 per group) revealed that: (1) The use of TCPL implants resulted in the formation of three distinct cell layers of fibrous tissue. (2) The fibrous tissue thickness was found to be directly proportional to the duration of the implant. (3) The infiltration of macrophages, polymorphonuclear leukocytes, and fibroblasts were present in all phases studied. (4) Ordered collagen was observed only at the end of the 6, 9, and 12 month phases. (5) Remarkable progression of vascularity was present in the second and third layers of the fibrous tissue. In conclusion, these observations confirm our previous finding using different bioceramic material.