RNF126, 168 and CUL1: The Potential Utilization of Multi-Functional E3 Ubiquitin Ligases in Genome Maintenance for Cancer Therapy

Ubiquitination is a post-translational modification (PTM) that is involved in proteolysis, protein-protein interaction, and signal transduction. Accumulation of mutations and genomic instability are characteristic of cancer cells, and dysfunction of the ubiquitin pathway can contribute to abnormal cell physiology. Because mutations can be critical for cells, DNA damage repair, cell cycle regulation, and apoptosis are pathways that are in close communication to maintain genomic integrity. Uncontrolled cell proliferation due to abnormal processes is a hallmark of cancer, and mutations, changes in expression levels, and other alterations of ubiquitination factors are often involved. Here, three E3 ubiquitin ligases will be reviewed in detail. RNF126, RNF168 and CUL1 are involved in DNA damage response (DDR), DNA double-strand break (DSB) repair, cell cycle regulation, and ultimately, cancer cell proliferation control. Their involvement in multiple cellular pathways makes them an attractive candidate for cancer-targeting therapy. Functional studies of these E3 ligases have increased over the years, and their significance in cancer is well reported. There are continuous efforts to develop drugs targeting the ubiquitin pathway for anticancer therapy, which opens up the possibility for these E3 ligases to be evaluated for their potential as a target protein for anticancer therapy.

Targeting Non-Oncogene Addiction for Cancer Therapy

While Next-Generation Sequencing (NGS) and technological advances have been useful in identifying genetic profiles of tumorigenesis, novel target proteins and various clinical biomarkers, cancer continues to be a major global health threat. DNA replication, DNA damage response (DDR) and repair, and cell cycle regulation continue to be essential systems in targeted cancer therapies. Although many genes involved in DDR are known to be tumor suppressor genes, cancer cells are often dependent and addicted to these genes, making them excellent therapeutic targets. In this review, genes implicated in DNA replication, DDR, DNA repair, cell cycle regulation are discussed with reference to peptide or small molecule inhibitors which may prove therapeutic in cancer patients. Additionally, the potential of utilizing novel synthetic lethal genes in these pathways is examined, providing possible new targets for future therapeutics. Specifically, we evaluate the potential of TONSL as a novel gene for targeted therapy. Although it is a scaffold protein with no known enzymatic activity, the strategy used for developing PCNA inhibitors can also be utilized to target TONSL. This review summarizes current knowledge on non-oncogene addiction, and the utilization of synthetic lethality for developing novel inhibitors targeting non-oncogenic addiction for cancer therapy.

Hypomorphic Mutations in TONSL Cause SPONASTRIME Dysplasia

SPONASTRIME dysplasia is a rare, recessive skeletal dysplasia characterized by short stature, facial dysmorphism, and aberrant radiographic findings of the spine and long bone metaphysis. No causative genetic alterations for SPONASTRIME dysplasia have yet been determined. Using whole-exome sequencing (WES), we identified bi-allelic TONSL mutations in 10 of 13 individuals with SPONASTRIME dysplasia. TONSL is a multi-domain scaffold protein that interacts with DNA replication and repair factors and which plays critical roles in resistance to replication stress and the maintenance of genome integrity. We show here that cellular defects in dermal fibroblasts from affected individuals are complemented by the expression of wild-type TONSL. In addition, in vitro cell-based assays and in silico analyses of TONSL structure support the pathogenicity of those TONSL variants. Intriguingly, a knock-in (KI) Tonsl mouse model leads to embryonic lethality, implying the physiological importance of TONSL. Overall, these findings indicate that genetic variants resulting in reduced function of TONSL cause SPONASTRIME dysplasia and highlight the importance of TONSL in embryonic development and postnatal growth.

Abstract P3-13-12: The margin of breast-conserving surgery when ductal carcinoma in situ is present within invasive ductal carcinoma

Objective: The presence of ductal carcinoma in situ (DCIS) in invasive ductal carcinoma (IDC) may increase the rates of positive margins and re-excision. Literature addressing this association is limited. This study aimed to explore the factors that are associated with positive margins and re-excision, as well as to evaluate the influence of positive margins on the survival of patients with breast cancer containing both invasive and in situ ductal carcinoma.

Methods: A retrospective medical chart review of patients diagnosed with DCIS within IDC who underwent BCS at the Revlon/UCLA Breast Center between January 2003 and December 2008 was performed.

Results: Of the 488 eligible patients, 267 patients (53.9%) underwent re-excision. The presence of residual disease upon re-excision was the highest in patients who initially had positive margins involved by both DCIS and IDC. In multivariate analysis, calcifications, tumor size, positive lymph nodes, and the presence of extensive intraductal component (EIC) were significantly associated with initial positive margins, with the latter having the highest hazard ratio (HR, 5.5–5.7, P = 0.000). Tumor size, molecular subtype, and final margin status were associated with disease-free survival. The final margin and regional lymph node status are significant prognosticators for breast cancer-specific survival.

Conclusions: In patients with ductal carcinoma of the breast containing both invasive and in situ components, the rate of initial positive margin after BCS was high and was significantly associated with calcifications, tumor size, regional lymph node status, and the presence of EIC.

Citation Format: Chen J, Ro A, Tan Q-W, Wang Z, Chang HR. The margin of breast-conserving surgery when ductal carcinoma in situ is present within invasive ductal carcinoma [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-13-12.

[Comparison of allogeneic or autologous hematopoietic stem cell transplant for high-risk peripheral T cell lymphomas]

目的

比较自体造血干细胞移植（auto-HSCT）和异基因造血干细胞移植（allo-HSCT）治疗高危外周T细胞淋巴瘤（PTCL）疗效的差异。

方法

回顾性分析苏州大学附属第一医院60例接受HSCT治疗的高危PTCL患者临床资料。

结果

60例PTCL患者均为高危组患者（IPI评分≥3分），接受移植时中位年龄31 (12~58）岁。包括PTCL非特指型22例、ALK阴性的间变大细胞淋巴瘤22例、血管免疫母细胞淋巴瘤16例。其中接受auto-HSCT的有39例（63.5%），接受allo-HSCT的有21例（36.5%）。移植前40例完全缓解（CR），2例部分缓解（PR），18例未缓解（NR）。40例CR患者中10例接受allo-HSCT, 30例接受auto-HSCT。20例PR+NR患者中11例接受allo-HSCT, 9例接受auto-HSCT。移植后中位随访时间为39 (1~96）个月，auto-HSCT和allo-HSCT组的5年无进展生存率分别为61％和60%（P=0.724）。auto-HSCT和allo-HSCT组的5年总生存率分别为62％和61%（P=0.724）。auto-HSCT和allo-HSCT组的5年移植相关死亡率分别为22.7％和41.8%（P=0.250）。截至末次随访时间，auto-HSCT中7例患者复发，allo-HSCT组中2例复发，auto-HSCT和allo-HSCT组的5年累计复发率分别为37.2％和10.1%（P=0.298）。

结论

高危PTCL患者选择auto-HSCT或allo-HSCT治疗长期生存无明显差异，但allo-HSCT组患者移植前多为NR状态，表明对于NR患者，allo-HSCT效果可能较好。

Clinical significance linked to functional defects in bone morphogenetic protein type 2 receptor, BMPR2

Bone morphogenetic protein type 2 receptor (BMPR2) is one of the transforming growth factor-β (TGF-β) superfamily receptors, performing diverse roles during embryonic development, vasculogenesis, and osteogenesis. Human BMPR2 consists of 1,038 amino acids, and contains functionally conserved extracellular, transmembrane, kinase, and C-terminal cytoplasmic domains. Bone morphogenetic proteins (BMPs) engage the tetrameric complex, composed of BMPR2 and its corresponding type 1 receptors, which initiates SMAD proteins-mediated signal transduction leading to the expression of target genes implicated in the development or differentiation of the embryo, organs and bones. In particular, genetic alterations of BMPR2 gene are associated with several clinical disorders, including representative pulmonary arterial hypertension, cancers, and metabolic diseases, thus demonstrating the physiological importance of BMPR2. In this mini review, we summarize recent findings regarding the molecular basis of BMPR2 functions in BMP signaling, and the versatile roles of BMPR2. In addition, various aspects of experimentally validated pathogenic mutations of BMPR2 and the linked human diseases will also be discussed, which are important in clinical settings for diagnostics and treatment.

Ring finger protein 126 (RNF126) suppresses ionizing radiation-induced p53-binding protein 1 (53BP1) focus formation

Cells have evolved sophisticated mechanisms to maintain genomic integrity in response to DNA damage. Ionizing radiation (IR)-induced DNA damage results in the formation of IR-induced foci (iRIF) in the nucleus. The iRIF formation is part of the DNA damage response (DDR), which is an essential signaling cascade that must be strictly regulated because either the loss of or an augmented DDR leads to loss of genome integrity. Accordingly, negative regulation of the DDR is as critical as its activation. In this study, we have identified ring finger protein 126 (RNF126) as a negative regulator of the DDR from a screen of iRIF containing 53BP1. RNF126 overexpression abolishes not only the formation of 53BP1 iRIF but also of RNF168, FK2, RAP80, and BRCA1. However, the iRIF formation of γH2AX, MDC1, and RNF8 is maintained, indicating that RNF126 acts between RNF8 and RNF168 during the DDR. In addition, RNF126 overexpression consistently results in the loss of RNF168-mediated H2A monoubiquitination at lysine 13/15 and inhibition of the non-homologous end joining capability. Taken together, our findings reveal that RNF126 is a novel factor involved in the negative regulation of DDR, which is important for sustaining genomic integrity.

The functional roles of PML nuclear bodies in genome maintenance

In the nucleus, there are several membraneless structures called nuclear bodies. Among them, promyelocytic leukemia nuclear bodies (PML-NBs) are involved in multiple genome maintenance pathways including the DNA damage response, DNA repair, telomere homeostasis, and p53-associated apoptosis. In response to DNA damage, PML-NBs are coalesced and divided by a fission mechanism, thus increasing their number. PML-NBs also play a role in repairing DNA double-strand breaks (DSBs) by homologous recombination (HR). Clinically, the dominant negative PML-RARα fusion protein expressed in acute promyelocytic leukemia (APL) inhibits the transactivation of downstream factors and disrupts PML function, revealing the tumor suppressor role of PML-NBs. All-trans retinoic acid and arsenic trioxide treatment has been implemented for promyelocytic leukemia to target the PML-RARα fusion protein. PML-NBs are associated with various factors implicated in genome maintenance, and are found at the sites of DNA damage. Their interaction with proteins such as p53 indicates that PML-NBs may play a significant role in apoptosis and cancer. Decades of research have revealed the importance of PML-NBs in diverse cellular pathways, yet the underlying molecular mechanisms and exact functions of PML-NBs remain elusive. In this review, PML protein modifications and the functional relevance of PML-NB and its associated factors in genome maintenance will be discussed.

Expression of Raf kinase inhibitor protein in human hepatoma tissues by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight methods

PURPOSE

Hepatocellular carcinoma (HCC) is the most common malignant liver tumor. To reduce the mortality and improve the effectiveness of therapy, it is important to search for changes in tumor-specific biomarkers whose function may involve in disease progression and which may be useful as potential therapeutic targets. Materials and Mehtods: In this study, we use two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to observe proteome alterations of 12 tissue pairs isolated from HCC patients: Normal and tumorous tissue. Comparing the tissue types with each other, 40 protein spots corresponding to fifteen differentially expressed between normal and cancer part of HCC patients.

RESULTS

Raf kinase inhibitor protein (RKIP), an inhibitor of Raf-mediated activation of mitogen-activated protein kinase/extracellular signal-regulated kinase, may play an important role in cancer metastasis and cell proliferation and migration of human hepatoma cells. RKIP may be considered as a marker for HCC, because its expression level changes considerably in HCC compared with normal tissue. In addition, we used the methods of Western blotting and real time-polymerase chain reaction to analysis the protein expression and gene expression of RKIP. The result showed RKIP protein and gene expression in tumor part liver tissues of HCC patient is lower than peritumorous non-neoplastic liver tissue of the corresponding HCC samples.

CONCLUSION

These results strongly suggest that RKIP may be considered to be a marker for HCC and RKIP are down-regulated in liver cancer cell.

[The roles of serum free light chain ratio in the diagnosis and prognosis of newly diagnosed multiple myeloma]

目的

分析血清游离轻链（sFLC）κ/λ比率（sFLCR）在初诊多发性骨髓瘤（MM）患者诊断和预后中的作用。

方法

回顾性分析2012年9月至2015年7月收治的82例初诊MM患者的临床资料，采用血清蛋白电泳（SPE）和免疫固定电泳（IFE）法检测血清单克隆蛋白（M蛋白）的表达，采用免疫比浊法检测sFLCκ、λ的表达水平，分析初诊时sFLCR在MM患者诊断和预后中的作用。

结果

初诊时82例患者中SPE法检测M蛋白阳性率为85.5%，IFE法检测M蛋白阳性率为93.9%，sFLC异常以及sFLCR异常者占96.3%。初诊时高比率组（sFLCR≥100或≤0.01，42例）与低比率组（0.01 <sFLCR<100，40例）患者40个月的总生存率分别为87％和61%，差异有统计学意义（P=0.034）。与低比率组患者比较，高比率组患者初诊时血肌酐值、浆细胞数、β₂微球蛋白增高，血红蛋白降低，肾功能不全及需要透析者、DS分期Ⅲ期B组者、ISS分期Ⅲ期者、FISH检查异常者、λ轻链异常者较多，κ轻链异常者较少（P值均<0.05）。两组患者经过3~4个疗程诱导治疗后，高比率组和低比率组患者的治疗有效率（非常好的部分缓解及其以上）差异有统计学意义（45.2％对72.5%，P=0.012）。初诊肾功能不全者（肌酐≥178 µmol/L, 14例）与肾功能正常者（68例）的2年总生存率差异无统计学意义（85.7％对91.2%，P=0.894）。

结论

初诊时sFLC的检测相对于SPE和IFE法检测M蛋白对诊断MM有更高的敏感性；初诊时sFLCR明显异常的患者可能具有更高的肿瘤负荷和更强的侵袭性，可提示患者预后不良；初诊时伴有肾功能不全的MM患者经积极治疗后可获得与肾功能正常患者同样的疗效。

Improving gastric cancer preclinical studies using diverse in vitro and in vivo model systems

BACKGROUND

"Biomarker-driven targeted therapy," the practice of tailoring patients' treatment to the expression/activity levels of disease-specific genes/proteins, remains challenging. For example, while the anti-ERBB2 monoclonal antibody, trastuzumab, was first developed using well-characterized, diverse in vitro breast cancer models (and is now a standard adjuvant therapy for ERBB2-positive breast cancer patients), trastuzumab approval for ERBB2-positive gastric cancer was largely based on preclinical studies of a single cell line, NCI-N87. Ensuing clinical trials revealed only modest patient efficacy, and many ERBB2-positive gastric cancer (GC) patients failed to respond at all (i.e., were inherently recalcitrant), or succumbed to acquired resistance.

METHOD

To assess mechanisms underlying GC insensitivity to ERBB2 therapies, we established a diverse panel of GC cells, differing in ERBB2 expression levels, for comprehensive in vitro and in vivo characterization. For higher throughput assays of ERBB2 DNA and protein levels, we compared the concordance of various laboratory quantification methods, including those of in vitro and in vivo genetic anomalies (FISH and SISH) and xenograft protein expression (Western blot vs. IHC), of both cell and xenograft (tissue-sectioned) microarrays.

RESULTS

The biomarker assessment methods strongly agreed, as did correlation between RNA and protein expression. However, although ERBB2 genomic anomalies showed good in vitro vs. in vivo correlation, we observed striking differences in protein expression between cultured cells and mouse xenografts (even within the same GC cell type). Via our unique pathway analysis, we delineated a signaling network, in addition to specific pathways/biological processes, emanating from the ERBB2 signaling cascade, as a potential useful target of clinical treatment. Integrated analysis of public data from gastric tumors revealed frequent (10 - 20 %) amplification of the genes NFKBIE, PTK2, and PIK3CA, each of which resides in an ERBB2-derived subpathway network.

CONCLUSION

Our comprehensive bioinformatics analyses of highly heterogeneous cancer cells, combined with tumor "omics" profiles, can optimally characterize the expression patterns and activity of specific tumor biomarkers. Subsequent in vitro and in vivo validation, of specific disease biomarkers (using multiple methodologies), can improve prediction of patient stratification according to drug response or nonresponse.

HNF4α is a therapeutic target that links AMPK to WNT signalling in early-stage gastric cancer

BACKGROUND

Worldwide, gastric cancer (GC) is the fourth most common malignancy and the most common cancer in East Asia. Development of targeted therapies for this disease has focused on a few known oncogenes but has had limited effects.

OBJECTIVE

To determine oncogenic mechanisms and novel therapeutic targets specific for GC by identifying commonly dysregulated genes from the tumours of both Asian-Pacific and Caucasian patients.

METHODS

We generated transcriptomic profiles of 22 Caucasian GC tumours and their matched non-cancerous samples and performed an integrative analysis across different GC gene expression datasets. We examined the inhibition of commonly overexpressed oncogenes and their constituent signalling pathways by RNAi and/or pharmacological inhibition.

RESULTS

Hepatocyte nuclear factor-4α (HNF4α) upregulation was a key signalling event in gastric tumours from both Caucasian and Asian patients, and HNF4α antagonism was antineoplastic. Perturbation experiments in GC tumour cell lines and xenograft models further demonstrated that HNF4α is downregulated by AMPKα signalling and the AMPK agonist metformin; blockade of HNF4α activity resulted in cyclin downregulation, cell cycle arrest and tumour growth inhibition. HNF4α also regulated WNT signalling through its target gene WNT5A, a potential prognostic marker of diffuse type gastric tumours.

CONCLUSIONS

Our results indicate that HNF4α is a targetable oncoprotein in GC, is regulated by AMPK signalling through AMPKα and resides upstream of WNT signalling. HNF4α may regulate 'metabolic switch' characteristic of a general malignant phenotype and its target WNT5A has potential prognostic values. The AMPKα-HNF4α-WNT5A signalling cascade represents a potentially targetable pathway for drug development.

Yeast Mitochondrial Transcription Factor Mtf1 Determines the Precision of Promoter-Directed Initiation of RNA Polymerase Rpo41

Despite their clear T7-bacteriophage origin, mitochondrial RNA polymerases have evolved to require transcription factors. All mitochondrial polymerases contain an extra N-terminal domain that has no counterpart in the self-proficient phage enzyme, which is therefore hypothesized to interact with transcription factors. We studied a series of N-terminal deletion mutants of yeast mitochondrial RNA polymerase, Rpo41, and have found that the N-terminal region does not abolish the effects of Mtf1; rather it contributes directly to enzyme catalysis. Mtf1 can rescue the defective Rpo41 enzymes resulted from N-terminal domain deletions. Although Rpo41 appears to have retained all promoter recognition elements found in T7 RNAP, the elements are not independently functional, and Mtf1 is necessary and sufficient for holoenzyme promoter-directed transcription activity.

A pathway-based approach for identifying biomarkers of tumor progression to trastuzumab-resistant breast cancer

Although trastuzumab is a successful targeted therapy for breast cancer patients with tumors expressing HER2 (ERBB2), many patients eventually progress to drug resistance. Here, we identified subpathways differentially expressed between trastuzumab-resistant vs. -sensitive breast cancer cells, in conjunction with additional transcriptomic preclinical and clinical gene datasets, to rigorously identify overexpressed, resistance-associated genes. From this approach, we identified 32 genes reproducibly upregulated in trastuzumab resistance. 25 genes were upregulated in drug-resistant JIMT-1 cells, which also downregulated HER2 protein by >80% in the presence of trastuzumab. 24 genes were downregulated in trastuzumab-sensitive SKBR3 cells. Trastuzumab sensitivity was restored by siRNA knockdown of these genes in the resistant cells, and overexpression of 5 of the 25 genes was found in at least one of five refractory HER2 + breast cancer. In summary, our rigorous computational approach, followed by experimental validation, significantly implicate ATF4, CHEK2, ENAH, ICOSLG, and RAD51 as potential biomarkers of trastuzumab resistance. These results provide further proof-of-concept of our methodology for successfully identifying potential biomarkers and druggable signal pathways involved in tumor progression to drug resistance.

Abstract 1781: Identification of focal adhesion and actin cytoskeleton regulation family genes as druggable target for gastric cancer

Gastric cancer(GC) is the 4th most common malignancy in the world and the 2nd most common cause of cancer related death worldwide (1). The known causes of GC are diet, hygiene, Helicobacter pylori, Epstein-Barr virus and hereditary factors. Other genetic causes of GC are known to be heterogenic, partially due to differences in ethnic/genetic background. Surgical removal of the tumor is the first-line treatment. Targeted therapy agents and chemotherapeutic agents that show survival advantage in other cancer types are being evaluated in GC(2,3), which only target few known oncogenes. Targeted therapy for GC is still an unmet need, and in light of personalized medicine, identifying genes specific to GC is critical for its treatment. From our NGS data, we have discovered protein family members involved in focal adhesion and actin cytoskeleton regulation pathways, which are involved in mitosis and metastasis.

We developed a subpathway network analysis method called PATHOME(unpublished), to identify pathways related to GC. For the first stage, two datasets (84 Korean GC: GSE13861 and 56 Japanese GC:GSE15081)(4,5). Two datasets (25 Korean GC: GSE36968 and 160 Chinese GC:GSE27342)(6,7,8) were used as validation sets. We identified top 10 common pathways. We have then categorized genes within these pathways according their functional category and druggability, either as drug transporter or druggable target. As a result, we identified genes involved in the focal adhesion and regulation of actin cytoskeleton pathways and cell junction, all critical for cell division and metastasis of tumor cells. Genes G1-9 are tight junction genes, and G10-20 are protein family group related to Ras-like GTP-binding protein, G10 - 20. G10, 11 and 12 are ras-like GTPases, and G13-20 are interacting proteins or downstream proteins. We then compared differential expression of these genes between the Asian and Caucasian dataset. G1-9 show co-regulation pattern among the two ethnic group. G9 in particular, is normally expressed in the stomach, and is downregulated (p=0.0045) in GC tumor samples. In contrast, G10 is upregulated in the Korean dataset and is shown to be upregulated in Japanese and Chinese GC sample (public) as well(9,10), but not in our Caucasian dataset(unpublished). The TCGA stomach cancer provisional data via cBioPortal(11) shows that most of the G10 alterations in GC cases are mutations (9% of total cases) with 2 known cases of downregulation. It is interesting that most of the G10 alterations were found in Caucasian patients (11/18 cases).

In our study, we have identified genes that are significant in GC and are druggable targets/drug transporters. It is significant that the pathways we identified are detected in both ethnic groups, with different expression pattern. This finding is critical for personalized treatment and drug development for GC.

Citation Format: Hae Ryung Chang, Seungyoon Nam, Myeong-Cherl Kook, Hee Seo Park, Hae Rim Jung, Youme Gim, Han Liang, Garth Powis, Yon Hui Kim. Identification of focal adhesion and actin cytoskeleton regulation family genes as druggable target for gastric cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1781. doi:10.1158/1538-7445.AM2014-1781

Abstract 523: Detection of PIWI-piRNAS in the mitochondria of human normal and cancer cells

Piwi-interacting RNAs (piRNAs) are a class of small non-coding RNAs that regulate differentiation in primordial germ cells, found mainly in the nucleus and cytoplasm. However, despite the essentiality of mitochondria to intrinsic apoptosis and energy metabolism, the presence of piRNAs (and their associated Piwi proteins) in this organelle remains largely unknown. In this study, a public database comparison of mitochondrial RNA-seq data from human normal (HEK293) and cancer (HeLa and 143B) cells revealed the presence of 29 mature piRNA sequences, with 12 of those piRNA sequences perfectly matching 7 tRNAs (Phe, Val, Leu, His, Ser, Glu, and Thr), suggesting piRNAs and tRNAs derive from a common precursor mitochondrial polycistronic transcript. Consistent with their known interaction with piRNAs, further examination revealed the presence of PIWI proteins in mitochondria. Moreover, the majority of the 29 piRNA sequences overlapped multiple longer sequences (expressed sequence tags, ESTs) that uniquely mapped to the mitochondrial genome. To our knowledge, this is the first report of Piwi and piRNAs in the mitochondria of mammalian normal and cancer cells.

Citation Format: ChangHyuk Kwon, Hyosun Tak, Mina Rho, Hae Ryung Chang, Yon Hui Km, Kyung Tae Kim, Eun Kyung Lee, Curt Balch, Seungyoon Nam. Detection of PIWI-piRNAS in the mitochondria of human normal and cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 523. doi:10.1158/1538-7445.AM2014-523

Abstract 2783: Variability of HER2 expression between in vitro and in vivo models within gastric cancer cell lines

In the process of developing individualized cancer therapeutics, tumor derived cell line based preclinical (in vitro and in vivo) methods have been widely used. Patient derived genome analysis revealed significant cancer biomarkers for targeted drug development. Classic cancer biomarker, HER2, overexpression was discovered as a cancer biomarker and as a druggable target in breast cancer, which lead to the development of Trastuzumab. HER2 is overexpressed in 10-25% of gastric cancer, and treatment with Trastuzumab showed positive yet limited activity in advanced gastric cancer treatment in the ToGA study. These results present HER2 as an attractive target for gastric cancer. However, Gillet and colleagues reported the challenges in the use of in vitro and in vivo studies for drug validation and development. They reported variance in gene expression patterns between the in vitro and in vivo context within a single cancer cell line. In our study using gastric cancer derived cell lines, we observed differences in HER2 expression between in vitro and in vivo xenograft model. Also, we show the potential promising in vivo xenograft model in the development of HER2 targeting agents for gastric cancer.

Eleven out of 25 gastric cancer cell lines showed HER2 expression, which was demonstrated using the IHC assay on a cell microarray. Sixteen out of 25 cell lines successfully produced xenograft models. Gastric cancer cell lines (SNU-5, SNU-16, SNU-638, SNU-1967, MKN-1, MKN-28, and NUGC-3) that had no HER2 expression when cultured in vitro showed HER2 expression in vivo. Two cell lines (NCC-19 and NCI-N87) that had HER2 expression in vitro showed a decrease in HER2 expression in vivo. Three cell lines (SNU-484, SNU-668, and SNU-719) showed various levels of increase in HER2 expression. Two cell lines showed minor to no changes in HER2 expression. NUGC-4 had consistent significant HER2 expression levels in both assays, while MKN-45 had consistent insignificant to no HER2 expression. Our study demonstrates inconsistency in HER2 gene expression between in vitro and in vivo cancer cell line models for the first time in gastric cancer.

Citation Format: Youme Gim, Hee Seo Park, Hae Rim Jung, Hae Ryung Chang, Seungyoon Nam, Yong Doo Choi, Ja-Lok Ku, Yon Hui Kim. Variability of HER2 expression between in vitro and in vivo models within gastric cancer cell lines. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2783. doi:10.1158/1538-7445.AM2014-2783

PATHOME: an algorithm for accurately detecting differentially expressed subpathways

The translation of high-throughput gene expression data into biologically meaningful information remains a bottleneck. We developed a novel computational algorithm, PATHOME, for detecting differentially expressed biological pathways. This algorithm employs straightforward statistical tests to evaluate the significance of differential expression patterns along subpathways. Applying it to gene expression data sets of gastric cancer (GC), we compared its performance with those of other leading programs. Based on a literature-driven reference set, PATHOME showed greater consistency in identifying known cancer-related pathways. For the WNT pathway uniquely identified by PATHOME, we validated its involvement in gastric carcinogenesis through experimental perturbation of both cell lines and animal models. We identified HNF4α-WNT5A regulation in the cross-talk between the AMPK metabolic pathway and the WNT signaling pathway, and further identified WNT5A as a potential therapeutic target for GC. We have demonstrated PATHOME to be a powerful tool, with improved sensitivity for identifying disease-related dysregulated pathways.

Abstract P4-16-07: Mesenchymal-epithelial transition (MET) and epithelial-mesenchymal transition (EMT) are closely related to chemotherapy resistance of triple negative breast cancer

Triple negative breast cancer (TNBC) is among the most aggressive clinical phenotypes and the presence of residual resistant cancer cells of TNBC after chemotherapy is associated with tumor recurrence and metastasis. In recent years more and more evidence highlight a crucial role of CD44 (+)/CD24 (-/low) (stem/progenitor cell-phenotype) population in cancer drug resistance but the mechanism remains elusive. In the current study, we screened for CD44 and CD24 using Fluorescence-activated cell sorting (FACS) in 8 TNBC cell lines before and after Docetaxel and Doxorubicin treatment. Our data showed that after Docetaxel treatment, several CD44 (+)/CD24 (-/low) cell lines changed their phenotypes to CD44 (+)/CD24 (+) and most of the CD44 (+)/CD24 (+) cell lines kept their double positive phenotypes. In contrast, after Doxorubicin treatment, all the CD44 (+)/CD24 (-/low) cell lines kept their phenotypes and all the CD44 (+)/CD24 (+) cell lines changed their phenotypes to CD44 (+)/CD24 (-/low). Furthermore, among the studied 8 cell lines, CD44 (+)/CD24 (+) cell population is always more resistant to Docetaxel and CD44 (+)/CD24 (-/low) population is always more resistant to Doxorubicin. Our finding of EMT transition from CD44 (+)/CD24 (+) to CD44 (+)/CD24 (-/low) in breast cancer cell lines and its inducible by Doxorubicin is consistent with the literature. However, our results showed for the first time that both EMT and the inverse MET in TNBC could be induced by specific chemotherapy drugs based on the phenotypes of CD44 and CD24. Besides, our gene microarray data also showed that TGFb2, BCL2, KLF6 and TAF4 pathways were dramatically changed in both CD44 (+)/CD24 (+) to CD44 (+)/CD24 (-/low) transition and CD44 (+)/CD24 (-/low) to CD44 (+)/CD24 (+) transition. Further study of these pathways in the transitions may give us new clues to overcome the chemotherapy resistance and lead us to develop successful therapeutic strategies of different types of TNBC.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-16-07.

Abstract P5-03-12: Prognostic role of stem cell markers in triple-negative breast cancer (TNBC)

Introduction: Triple-negative breast cancer (TNBC) is among the most aggressive types of breast cancer with frequent recurrence and death despite chemotherapy. Studies have shown that cancer stem cells play a key role in many of the drug resistant cancers including TNBC. In this study, we report the expressions of four stem cell markers in 158 TNBC tumors.

Design: Clinicopathological data were obtained from 158 triple negative breast cancers between 2002 and 2010. Tissue microarray was constructed and immunohistochemistry stains (IHC) for CD44 and CD24, CD 133 and ALDH1 were performed using the streptavidin-biotin method. Each set of TNBC consists of normal, ductal carcinoma in situ and invasive areas for assessment of IHC stains. Statistical analysis was done on the following parameters: Histological types, modified Bloom and Richardson grades, lymph-vascular invasion, lymph node status, tumor size, Ki67, presence of lymphocytic host response, age &gt;50 or &lt;50, BRCA status, prognosis (recurrence and death) and chemotherapeutic response. P values less than 0.05 were considered statistically significant.

Results: the mean age of this cohort of TNBC patients was 55 with 64% white, 13.2% black, 12.6% Asian/Pacific, 3.8% Hispanic/Latino and 1.9% other. The majority of these tumors (82.3%) were grade 3, 15.2% were grade 2, and less than 1% was grade 1. CD24, CD44 and CD133 expressions were significantly higher in TNBC than in normal breast tissues (p = 5.53 e-10, p = 1.14 e-11, p = 2.25 e-08 respectively). While both CD24 and CD133 expressions predicted poor survival (p = 0.073 and p = 0.043 respectively), neither was associated with recurrence. In contrast to CD24, CD44 and CD133 expressions, ALDH-1 expression was rare in TNBC and surrounding normal tissues. When expressed, ALDH-1 was associated with poor survival but cases were too few to reach significance. None of the four stem cell markers studied were associated with any of the conventional histopathologic features and BRCA1 or BRCA2 mutations.

Conclusions: Our study suggests that stem cell marker(s) may be prognostically important in TNBC patients. When it is fully characterized it may provide new insight in developing effective therapeutic strategies targeting stem cell related signaling pathways.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-03-12.

Abstract 5534: Metformin increases AMPKα activity by inhibition of AMPKα and cell cycle proliferation in Asian gastric cancer

The LKB1/AMPK signaling pathway has been well elucidated and recent evidence suggests its involvement in cancer cell biology, demonstrating that the reinforcement of the tumor suppressive functions of LKB1/AMPK is a valuable therapeutic strategy for cancers. Interest in metformin as a novel anticancer agent for breast cancer and other solid tumors continue to grow, currently being investigated in several cancer types in both neoadjuvant and metastatic settings. The biological effect of metformin on cancer cells is driven by its ability to activate AMPK through upstream kinase LKB1, tumor suppressor gene in epithelial tissues. Metformin increases intracellular AMP level, which allosterically activates AMPK. We have previously identified the AMPKα as a modulator in gastric cancer (GC) and through experimental evidence. We show the impact of LKB1/AMPK modulation of HNF4α, a dramatic suppression of cancer cell growth.

GC samples were collected and sequenced on SOLiD v 3.0 for both WT-seq and small RNA-seq. Computational analysis showed that 356 out of 18,890 genes were identified as GC related differentially expressed genes in the five-group comparison (normal, tumor stage I, II, III or IV). 28 genes were identified as stage-specific differentially expressed genes, and 13 out of the 28 genes were within the network between HNF4α and HNF1α. In order to test the anti-proliferation activity of metformin in GC cell lines associated with activation of PRKAA1, PRKAA2 and LKB1, and by HNF4α suppression, 4 GC cell lines (NCI-N87, AGS, HS 746T and MKN 45) were treated with metformin. Both PRKAA1/2 showed increased gene expression level when the cells were treated with 10mM of metformin. As for STK11 (LKB1 gene) and HNF4A gene expression level, LKB1 increased and HNF4A decreased with metformin treatment on all four cell lines. Metformin treated NCI-N87 and AGS show that it is involved in cell cycle arrest. Western-blot analysis shows, decreased protein expression of Cyclin A/B and D1 on metformin treated. Lastly, NCI-N87 xenograft study show metformin treated suppression of tumor progression compared to non-treated mouse. During the 28 day treatment of metformin, PRKAA1 and PRKAA2 expression level increased compared to the untreated with. Consistent with in vitro assay, LKB1 level was elevated in the metformin treated tumor compared to the non-treated, and HNF4α level decreased over time in the metformin treated tumor.

Study shows that AMPK is a strong therapeutic tumor suppressor target and that metformin is a potential drug for Asian early gastric cancer patient. In our research in progress, we observe potential relationships between the Wnt pathway and AMPKα in light of WNT druggability with metformin. In conclusion LKB1/AMPK by HNF4α inhibition suggests metformin could be a candidate for gastric cancer treatment, probably in combination with conventional chemotherapy and/or as a maintenance therapy.

Citation Format: Hae Rim Jung, Hae Ryung Chang, Hye-Hyun Seo, Robert Lemos, Hee Seo Park, Han Liang, Garth Powis, Yon Hui Kim. Metformin increases AMPKα activity by inhibition of AMPKα and cell cycle proliferation in Asian gastric cancer. [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 5534. doi:10.1158/1538-7445.AM2013-5534

Abstract 5540: Crosstalk between Wnt and AMPK pathway in Asian gastric cancer by metformin

Stomach cancer is the most prevalent cancer in Eastern Asia(1). Given the diverse route to oncognesis, it is highly attractive to develop targeted therapy based on each patient's biology(2). Several molecular targeting agents that show survival advantage in other cancer types are being under clinical investigation in gastric cancer (GC) (3-6). These agents focus on a few known oncogenic genes, yet its true efficacy of their biologically targeted therapies in gastric cancer is still unknown. To identify high-quality therapeutic targets, we utilized PATHOME (pathway and genome information), a computational method to identify therapeutic target through sub-pathway employing simple statistic-based approach (unpublished).

PATHOME design had two stages: 1) discovery stage aimed at selecting target signaling pathway, and 2) validation stage aimed at identifying small number of reproducible genes from sub-pathways by using independent dataset to provide a novel theragnostic strategy in GC patients. Four sets of GEO database datasets were used: GSE13861 (84 Korean GC), GSE15081 (56 Japanese GC) for the discovery stage, and GSE36968 (25 Korean GC), and GSE27342 (160 Chinese GC) were added for validation. Using Vogelstein et al. as the gold standard, DAVID and GSEA vs. PATHOME were applied for comparison of potency in prediction of signaling pathways(7). Previous study showed that the energy sensing mechanism by AMPKα is involved in Asian GC(8). Metformin is a drug used to treat diabetes, which affects AMPKα in the cell. We treated GC cell line with metformin and saw the expression level of proteins that were selected by PATHOME to test its predictability of biological context.

13 up-regulated genes were identified using 3 datasets (GSE 13861, GSE 15081 and GSE36968), and 5 (GENE1, GENE2, GENE3, GENE4 and GENE5) from all 4 datasets using PATHOME. Transcription factor binding site analysis showed that two of the 5 genes contained GENE6 binding sites. Implications of AMPKα as a potential therapeutic target has been published(9). Metformin is shown to increase PRKAA2 level, which encodes AMPKα, also inhibits HNF4α(8). To see if metformin has any effect on the genes with HNF4α binding site, we observed the expression level of GENE4 and related proteins. Metformin treated GC cell lines (NCI-N87 and AGS) result in decreased viability compared to untreated cells. On Western-blot analysis, metformin treated cells show a decrease of GENE4, GENE6, but not GENE7 or GENE8.

Utilizing PATHOME, which showed greater consistency compared to DAVID and GSEA in terms of cancer-related pathways, we showed Wnt pathway to have a potential impact on GC in East Asia. Therefore, our approach has simplified insight of multiplexed signals apply in molecular targeted therapies. We report a cross-talk between AMPKα and Wnt pathway in gastric cancer, which is known to be involved in other cancer types. This finding will lead to other potential drug targets for GC.

Citation Format: Hae Ryung Chang, Seungyoon Nam, Hae Rim Jung, ChangHyuk Kwon, Hye-Hyun Seo, Frances S. Sung, Hee Seo Park, Taesung Park, Yon Hui Kim. Crosstalk between Wnt and AMPK pathway in Asian gastric cancer by metformin. [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 5540. doi:10.1158/1538-7445.AM2013-5540

A reciprocal translocation and possible insertion(s) tightly associated with host-specific virulence in Cochliobolus heterostrophus

A reciprocal translocation and one or more apparent insertions are shown to be tightly associated with Tox1, a locus controlling T-toxin production and host-selective virulence in race T of the maize pathogen Cochliobolus heterostrophus. Chromosome arrangements were examined by separating chromosomal DNAs of a variety of Tox+ and Tox&minus; strains by pulsed-field gel electrophoresis and hybridizing with probes known to detect RFLPs genetically linked to Tox1. The existence of the translocation was demonstrated by chromosome hybridization patterns; the existence of the putative insertion(s) was deduced from chromosome migration rates. Both differences in chromosome arrangement were detected between 8 Tox+ and 8 Tox&minus; near-isogenic laboratory strains, suggesting that the differences are tightly linked to Tox1. The reciprocal translocation was also detected between all 7 Tox+ and 8 Tox&minus; field isolates examined, suggesting that the translocation is common in natural populations. The field isolates may also differ by the insertion(s); however, numerous additional chromosome size polymorphisms in the field isolates prevented a firm conclusion. The tight association of the translocation and insertion(s) with T-toxin production suggests that chromosome rearrangements may have been involved in the evolution of race T and Tox1. These genomic differences may be causally related to the previously reported reduced fitness of race T relative to race O on N-cytoplasm maize. Key words : chromosome rearrangement, southern corn leaf blight, pulsed-field electrophoresis, T-toxin, evolution.

Early diagnosis of polyomavirus type BK infection in tailoring immunosuppression for kidney transplant patients: screening with urine qualitative polymerase chain reaction assay

Polyomavirus type BK (BKV) nephropathy is increasingly a significant cause of graft dysfunction and even failure. Early diagnosis followed by reduction of immunosuppression has been associated with an improved prognosis. We screened 250 patients with the urine qualitative polymerase chain reaction (PCR) for BKV DNA. We followed with blood BKV PCR if the urine screen was positive and then reduced immunosuppression in viremic patients. One hundred ninety-nine patients (80%) had no viuria; 43 (17%) viuria; and 8 (3%) both viuria and viremia. Graft biopsy performed in three patients (1%) with viremia and impaired graft function all revealed BKV nephropathy. After 6 months of follow-up, seven out of eight viremic patients (88%) had negative repeat blood PCR and stabilized graft function. An early diagnosis of BKV infection with reduction of immunosuppression may reverse viremia and retard progression of BKV nephropathy. BKV screening by PCR assays should be considered in kidney transplant recipients, especially those with impaired graft function.

Predictors of renal function improvement following tacrolimus conversion in cyclosporine-treated kidney transplant recipients

The objective of this study was to evaluate the relationship between variability of cyclosporine (CsA) absorption and tacrolimus (TAC) conversion seeking factors that predict improvement in allograft function after TAC conversion. We performed a retrospective study of 44 adult kidney transplant recipients undergoing conversion from CsA to TAC-based immunosuppression. Before TAC conversion, patients had complete, consecutive, 6 monthly C2 levels and a follow-up duration beyond 6 months after TAC conversion. The patients were divided into 2 groups: one (n=23) with low variability of CsA absorption and one (n=21) with high variability of CsA absorption. At TAC conversion, the estimated glomerular filtration rate (eGFR) was similar in both patient groups. Six months after TAC conversion, eGFR improved in both groups. Stepwise regression analysis revealed the DeltaSCr6 (change in serum creatinine level at 6 months) to be independently associated with the preconversion serum creatinine (SCr; P<.0001) and the percent coefficient of variation (%CV) of SCr (P=.0034). DeltaSCr6 was inversely associated with posttransplantation years (P=.0033), and 6-month TAC blood levels (P=.0053). The DeltaSCr6 was not associated with variability of oral CsA absorption. The cutoff value of baseline SCr at TAC conversion differentiated an increase in or reduction of SCr to be about 1.0 mg/dL. Our study of CsA-treated kidney transplant recipients who underwent TAC conversion showed that a preconversion SCr>1.0 mg/dL, a high variability of SCr, and early TAC conversion predicted greater short-term benefit on graft function.

Lack of hepatotoxicity upon sirolimus addition to a calcineurin inhibitor-based regimen in hepatitis virus-positive renal transplant recipients

BACKGROUND

We retrospectively analyzed the impact of sirolimus addition (SRL) with a 25% dosing reduction in calcineurin inhibitors on liver function among patients with or without hepatitis B virus (HBV) or hepatitis C virus (HCV) infection.

METHODS

Forty-eight renal transplant recipients (HBsAg-positive, n = 5; anti-HCV-positive, n = 7) with allograft dysfunction (serum creatinine: mean 2.7, median 2.0 mg/dL) and normal liver function were enrolled. The duration of the SRL add-on therapy was 8.0 +/- 3.6 months. SRL trough levels were maintained within 6.5 +/- 3.7 ng/mL. The trough levels of tacrolimus and the 2-hour cyclosporine postdose levels were tapered to 4.6 +/- 1.9 ng/mL (24.6% reduction) and 650 +/- 170 ng/mL (24.3% reduction), respectively. SRL-related hepatitis was defined as a rise in liver transferase or alkaline phosphatase or bilirubin over twice the upper limit of normal. Thirty-six HBsAg-negative and anti-HCV-negative patients served as the controls.

RESULTS

Hepatotoxicity developed in 6 (12.5%) of the 48 patients and in 3 (8.3%) of 36 control subjects. One (20.0%) of five HBsAg-positive patients (P = .959) and two (28.6%) of seven anti-HCV-positive patients (P = .496) developed hepatotoxicity, respectively. Three (25.0%) of the 12 HBsAg-positive or anti-HCV-positive patients developed hepatotoxicity (P = .420).

CONCLUSIONS

Patients with seropositivity of HBsAg or anti-HCV had an insignificantly higher percentage of hepatitis. Use of SRL in the HBV/HCV patients is not contraindicated, but needs monitoring for HBV/HCV activation.

Surgical outcomes of deep sclerectomy with collagen implant

We evaulated the effectiveness and adverse effects of deep sclerectomy with collagen implant (DSCI), which is a kind of nonpenetrating filtering surgery. In this retrospective study, DSCI was performed in 15 eyes of 11 glaucoma patients. An trabeculo-Descemet's membrane (TDM) window is created by a deep sclerokeratectomy, and the collagen implant is placed in the sclera bed under a superficial flap (deep sclerectomy with collagen implant). In 3 of 15 eyes the DSCI was intraoperatively converted to conventional filtering surgery for a large perforation of the TDM. These eyes were not included in the results of the surgical outcomes. The mean age of the patients was 50.3 +/- 14.4 years, and the mean follow-up period was 11.1 +/- 5.9 months. A diagnosis of chronic open angle glaucoma was made in 7 eyes and a diagnosis of secondary glaucoma in 5 eyes. The mean preoperative IOP was 25.8 +/- 11.9 mmHg, the immediate postoperative IOP was 6.4 +/- 2.9 mmHg, and at the final follow-up, the IOP was 11.9 +/- 2.5 mmHg. The IOP in 5 eyes was under 6 mmHg temporarily. However, there was no serious complication such as shallow anterior chamber. DSCI is considered to be a good surgical procedure that has similar surgical outcomes to a conventional trabeculectomy without serious complications.

Evaluation of the severity of traumatic rhabdomyolysis using technetium-99m pyrophosphate scintigraphy

A quantitative scoring method was designed to assess the extent of muscle damage. Technetium-99m pyrophosphate (99mTc-PYP) scintigraphy was performed for 9 patients experiencing crush injury in the Chichi (Taiwan) earthquake. The magnitude of muscle uptake of 99mTc-PYP was graded as follows: grade 0, less than bone radioactivity (BRA); grade 1, equal to BRA; grade 2, higher than BRA; or grade 3, greatly higher than BRA. The area of muscle injury was estimated according to the rule of nines. The sum of the muscle injury size multiplied by its corresponding grading was defined as the anterior or posterior score according to the anterior or posterior images. Each image was interpreted by two physicians and average anterior and posterior scores were calculated. The muscle score was defined as the geometric mean of the average anterior and posterior scores. Significant correlations were obtained between the muscle score and duration of time trapped (r = 0.868, p < 0.01), peak serum creatine kinase level (r = 0.866, p < 0.01), peak serum phosphorus level (r = 0.877, p < 0.01) and number of hospital days (r = 0.875, p < 0.01). A negative correlation between the muscle score and blood pH (r = -0.706, p < 0.01) was also observed. We concluded that this scoring method may be used as an adjunct for evaluating the locations of trauma and the severity of crush syndrome, and for predicting the duration of hospital stay.

Biomicroscopic vitreous observation using a 3 CCD video camera and a personal computer for image capture and archiving

The purpose of this study is to evaluate the clinical usefulness of a newly developed biomicroscopic vitreous observation system. Vitreous observation was performed in 300 eyes with age- or disease-related vitreous changes using a 3 CCD video camera mounted on a slit-lamp biomicroscope and connected to a personal computer for real-time observation and especially for the capture and archiving of images. Various types of fundus lenses were used to scan the vitreous status systemically from the posterior pole to the vitreous base. This system allowed us to obtain and immediately review the images of the vitreoretinal relationship. The image quality was sufficient for clinical evaluation of the vitreous status. We were able to identify some variations of posterior vitreous detachments and clarify the changes of the vitreoretinal interface in the study eyes. This system is very useful for the dynamic observation and documentation of vitreous images in order to determine the role of vitreous in many vitreoretinal disorders. Furthermore it is more convenient and affordable than previous methods.

Decreased salivary function in patients with end-stage renal disease requiring hemodialysis

It has been speculated that impaired salivary flow is common in patients with end-stage renal disease (ESRD) requiring hemodialysis (HD). The aim of this study is to investigate the relation between oral manifestations and salivary function in patients with ESRD undergoing HD. Salivary function was measured by quantitative salivary scintigraphy in 60 patients with ESRD undergoing HD, as well as in 36 age- and sex-matched healthy controls for comparison. The 60 patients with ESRD undergoing HD were separated into two subgroups: group 1, 30 patients with oral manifestations, and group 2, 30 patients without oral manifestations. After an intravenous injection of 5 mCi of technetium 99m pertechnetate, sequential images at 1 minute per frame were acquired for 30 minutes. The 1- and 15-minute uptake ratios were calculated as the tracer uptakes in the four major salivary glands over the background regions of interest. Saliva excretion was stimulated by one 200-mg tablet of ascorbic acid administered orally 15 minutes post-tracer injection, then the maximal excretion ratios of the four major salivary glands were calculated. Our results show significantly poorer salivary function in patients with ESRD with oral manifestations compared with patients with ESRD without oral manifestations and healthy controls by means of objective and quantitative salivary scintigraphy.

Use of pulsed-field gel electrophoresis in the analysis of recurrent Staphylococcus aureus infections in patients on continuous ambulatory peritoneal dialysis

BACKGROUND/AIM

The purpose of this study was to evaluate pulsed-field gel electrophoresis (PFGE) for distinguishing between relapse and reinfection of Staphylococcus aureus infections in patients on continuous ambulatory peritoneal dialysis (CAPD).

METHODS

Between July 1993 and May 1997, 4 patients with recurrent CAPD-associated infections caused by S. aureus we enrolled in this study. There were nine episodes of peritonitis, one episode of temporary double lumen catheter infection, and one episode of Hickman catheter infection. A total of eleven S. aureus isolates were collected from peritoneal fluid (n = 9) and blood (n = 2). PFGE typing was applied.

RESULTS

In our study, from PFGE typing, the 11 S. aureus isolates were classified into seven patterns. Antibiogram profiling classified only four patterns. Patient A had a reinfection by another strain of S. aureus, and patient B had three episodes of peritonitis caused by the same strain of S. aureus due to exit site infections. Patient C had two episodes of CAPD peritonitis caused by two different strains, respectively. Patient D had four episodes of S. aureus infection (three CAPD peritonitis and one bacteremia); the first two episodes of peritonitis were caused by an identical strain of S. aureus, whereas the subsequent two infections were caused by other organisms.

CONCLUSION

PFGE has a high discriminatory power and can be an assistant method to antibiogram profiling for distinguishing relapse from reinfection in CAPD-associated peritonitis.

Alterations in beta-adrenergic receptor density and adenylate cyclase activity in the rat brain treated chronically with lead

Behavioral and memory impairment resulting from lead exposure is well known but the mechanism is not. We utilized the brain of lead exposed rats to investigate this problem. In an effort to elucidate the mechanism responsible for this alteration we examined blood and brain lead levels, brain beta-adrenoceptor density and cyclic AMP production in lead exposed rats. Wistar rats used in these trials were divided into six groups of ten animals each. Five groups were given drinking water containing 0.05, 0.1, 0.5, 1 and 2% lead acetate for a period of 60 days. One group (control group, 0% lead acetate) was given pure water. Application of a trend test indicated that both blood and brain lead levels increased significantly from group 0% to group 2% (group 0% <group 0.05% <group 0.1% <group 0. 5%<group 1%<group 2%), but that brain beta-adrenoceptor density and cyclic AMP levels stimulated by isoproterenol decreased (group 2%<group 1%<group 0.5%<group 0.1%<group 0.05%<group 0%). Kd did not vary among the six groups and this indicated that the affinity of the remaining beta-adrenoceptors for [125I]iodocyanopindolol was not changed. Linear regression analysis showed that beta-adrenoceptor density and stimulated cyclic AMP level in brain was found to be negatively correlated with brain lead level (P<0.001). The results show lead exposure that may be the result of an alteration of beta-adrenergic receptor and adenylate cyclase activity in brain.

Cutaneous blood flow and adrenoceptor response increase in segmental-type vitiligo lesions

It has been proposed that two types of vitiligo exist from the physiological and clinical points of view. Nonsegmental-type vitiligo is associated with autoimmune diseases while segmental-type vitiligo results from the dysfunction of sympathetic nerves in the affected area. Using laser Doppler flowmetry and iontophoresis for cutaneous microcirculatory assessments, we evaluated these two types of vitiligo in regard to their physiological changes. Ten patients with facial stable stage segmental-type vitiligo and ten stable nonsegmental-type vitiligo patients were selected for this study. Our results revealed that a nearly threefold increase in cutaneous blood flow was noticed in segmental-type vitiligo as compared to contralateral normal skin. In contrast, a 1.4-1.5 times difference was found among nonsegmental-type vitiligo, lesion side clinically normal skin and contralateral normal skin. There was a significant increase in cutaneous alpha- and beta-adrenoceptor response in segmental-type vitiligo lesions. However, no change in plasma catecholamines or adrenoceptor densities on blood cells was noticed. Our findings suggest that a dysfunction of the sympathetic nerves exists in the affected skin and plays a role in the pathogenesis of segmental-type vitiligo.

The change of beta-adrenergic system in lead-induced hypertension

Lead exposure is considered to be a risk factor of cardiovascular disease. To investigate the relationship between lead and cardiovascular disease/hypertension in lead exposure, beta-adrenergic system is explored in this study. We address three topics in this study: (a) the relationship between beta-adrenergic receptor and lead level in heart, aorta, and kidney of lead-exposed rats; (b) the relationship between beta-adrenergic receptor in heart, aorta, kidney, and blood pressure in lead-exposed rats; and (c) the change of cyclic AMP level in heart, aorta, and kidney of rats with different lead levels. Wistar rats were chronically fed with 2, 1, 0. 5, 0.1, 0.05, and 0.01% lead acetate and water for 2 months. Plasma catecholamine level was measured by high-performance liquid chromatography. Radioligand binding assay was measured by a method that fulfilled strict criteria of beta-adrenoceptor using the ligand [(125)I]iodocyanopindolol. Cyclic AMP (cAMP) level was determined by radioimmunoassay. The levels of lead were determined by electrothermal atomic absorption spectrometry. The results showed that increased plasma norepinephrine level, decreased aorta beta-adrenergic receptor and cAMP, and increased kidney beta-adrenergic receptor and cAMP contributed to the elevation of blood pressure in lead-induced hypertension. The decrement of beta-adrenoceptor and cAMP in heart resulted in decreased contractility in heart.

Outcomes and factors impacting local recurrence of ductal carcinoma in situ

BACKGROUND

The optimal management of ductal carcinoma in situ (DCIS) remains controversial. Investigators have focused on identifying patients who are eligible for treatment by excision alone. A retrospective analysis of patients with DCIS treated by various modalities was conducted to compare outcomes and determine factors significant for local recurrence (LR).

METHODS

Between 1985-1992, 88 consecutive diagnoses of DCIS were identified in 85 patients. Seventy-four percent were detected mammographically. The most common histologic subtypes were comedo (54%) and cribriform (23%). Tumor sizes were < 2.5 cm (49%), > 2.5-5 cm (26%), > 5 cm (23%), and unknown (2%). Final resection margins were tumor free (75%), close/positive (23%), and unknown (2%). Treatment methods included mastectomy (30%), localized surgery and radiation therapy (LSR) (43%), or wide localized surgery alone (LS) (27%). Radiation therapy (RT) was comprised of 50 grays to the breast, and 53% of treated patients received local "boost" irradiation.

RESULTS

The median follow up was 8.3 years. The overall recurrence rate was 13. 6%, whereas the median time to LR was 27.8 months. Recurrence rates according to treatment modality were: LS: 25%; LSR: 13%; and mastectomy: 4%. However, if surgical margins were tumor free, LSR had a LR rate of 3.4%. After RT, no LR occurred prior to 15 months, and 4 of 5 tumors were noninvasive. Nine patients treated by excision alone conformed to the criteria of Lagios et al. criteria and LR occurred in three of nine tumors. Of the factors analyzed, margin status was found to be the best predictor for LR (P = 0.05).

CONCLUSIONS

If surgical margins are tumor free, the LSR regimen is equivalent to mastectomy for local tumor control. Annual mammograms may be adequate for the follow-up of patients with irradiated breasts, but biannual studies still are recommended for patients treated with excision alone.

Nonpalpable breast cancer in women aged 40-49 years: a surgeon's view of benefits from screening mammography

While mammography screening among women aged 50 years or older has proven to reduce breast cancer mortality, screening in younger women has been repeatedly scrutinized. To test the effect of screening among younger women, we examined 84 consecutive patients aged 40-49 at the time of breast cancer diagnosis: 27 (32.1%) were diagnosed solely by mammography, and 57 (67.9%) had a palpable mass. The mean tumor sizes were 1.3 cm and 3.6 cm for the two groups respectively. While 68.8% nonpalpable invasive tumors were classified as Stage I cancer, only 34% of patients with palpable breast cancer had Stage I disease. None of the patients with nonpalpable breast cancer had disease beyond Stage II. In contrast, 28.3% of the patients with palpable invasive breast cancer presented with advanced disease. In addition, 6.3% versus 41.5% of patients with nonpalpable and palpable breast cancer respectively had nodal metastases. The five-year survival rates for the two groups were 100% and 73% respectively, favoring breast cancer detected mammographically. Screening of women aged 40-49 also resulted in more breast-conserving surgery and less chemotherapy. We conclude that screening in this age group should be continued, although individual assessment is needed.

Prognostic analysis of survival in small breast cancers

BACKGROUND

Routine axillary dissection in patients with invasive small breast cancer remains controversial. We previously reported a model for predicting nodal involvement in patients with T1a or T1b breast cancer that may guide the practice of selective nodal dissection. The objective of this study was to determine whether the prognosticators that predict nodal metastases also predict survival.

STUDY DESIGN

This study is a retrospective review of 2,153 women with small invasive breast cancer (< or = 1 cm) diagnosed between January 1984 and December 1995. Cases were identified from a statewide tumor registry, the Hospital Association of Rhode Island, and the tumor registry at Baystate Medical Center in Massachusetts. The impact on survival of patient age (< or = 40 versus > 40 years), nodal status (positive versus negative), tumor size (T1a versus T1b), and tumor grade (1 versus 2 or 3) were analyzed. Breast cancer-specific survival (BCSS) was analyzed using the Kaplan-Meier method and the proportional hazards regression method.

RESULTS

There were 388 patients with tumors 0.5 cm or less (T1a) and 1,765 with tumors 0.6-1.0 cm (T1b). Nodal status was known in 68% of cases (1,461 of 2,153), and tumor grade was recorded in 42% of cases (902 of 2,153). In univariate analysis, age, grade, and nodal status were significant in their association with BCSS. Tumor size did not influence BCSS among patients with small invasive tumors. Women older than 40 years had superior survival compared with younger women (93% versus 78% at 5 years; p = 0.01). Similarly, women with low grade (1) tumors did better than those with higher grade (2 or 3) tumors (98% versus 88% at 5 years; p = 0.03). The 5-year BCSS was 96% versus 78% for node-negative versus node-positive disease, and the 10-year BCSS was 91% versus 62% (p = 0.001). In the multivariate analysis, age and nodal status remained firmly associated with survival, although grade lost its significance.

CONCLUSIONS

Small tumor size does not affect survival. Although risk profiles for nodal involvement can be constructed to help guide the practice of selective axillary lymphadenectomy in patients with small invasive breast cancers, these factors cannot serve as a surrogate to nodal status in establishing patient prognosis. Nodal status remains the most powerful determinant of survival in breast cancer patients, even those with very small tumors.

The role of cytokines in the catabolic consequences of infection and injury

During infection and injury a series of metabolic events are activated that leads to a state of negative nitrogen balance and significant loss of lean body mass. This process is characterized by marked anorexia, net whole body protein breakdown, and liver anabolism. This host response initially is beneficial to the body because it helps it to fight disease and enhance healing. However, if such imbalance is maintained for long periods, it will invariably produce significant loss of lean body mass that may lead to a series of untoward clinical events. The role of the proximate cytokines, tumor necrosis factor (TNF), interleukin-1 (IL-1), and interleukin-6 (IL-6) as well as glucocorticoids as important mediators of many pathophysiological manifestations of infection and injury has been studied extensively. However, the involvement of other mediators, at least in skeletal muscle proteolysis during sepsis has been hypothesized, because blockade of glucocorticoids, TNF, IL-1, and IL-6 reduces but does not normalize protein breakdown rates nor does the direct application of these mediators to skeletal muscle in vitro enhance proteolysis. Furthermore other studies have suggested that the lymphokine, interferon-gamma (IFN-gamma, type II interferon or immune interferon), produces fever and enhances thermogenesis, body weight loss, and skeletal muscle depletion in rodents in a manner similar to that seen with TNF and IL-1. Cytokines appear to be major components of the host metabolic response during infection and injury. However, neither all the cytokines involved nor the exact mechanisms underlying their metabolic effects are completely understood. The regulation of muscle protein synthesis and breakdown, which largely determines the development of cachexia, appears to depend on the delicate balance between a number of regulatory substances including cytokines, glucocorticoids, catecholamines, insulin, and insulin-like growth factors.

A comparative analysis of lobular and ductal carcinoma of the breast: presentation, treatment, and outcomes

BACKGROUND

Compared with invasive ductal carcinoma, invasive lobular carcinoma of the breast is considered by many to be a more indistinct and multicentric form of cancer that is detected later and is treated less optimally by breast-preservation techniques. This study analyzed the presentation, treatment trends, and survival rates of women who had invasive lobular and ductal breast carcinoma. The objective was to determine the utility of breast-preservation therapy for invasive lobular carcinoma by analysis of historic data on tumor features and survival.

STUDY DESIGN

Data on 291,273 women diagnosed with invasive carcinoma between 1985 and 1993 were obtained from the National Cancer Data Base. Analysis included the patient's age at diagnosis; tumor histology, anatomic site, diameter, grade, and stage; treatment; and disease status 5 years after diagnosis.

RESULTS

The mean patient age at diagnosis was 61.0 years for invasive ductal carcinoma, 63.0 years for invasive lobular carcinoma, and 60.6 years for tumors with combined histology. The anatomic location, tumor diameter, and tumor grade were similar for each histotype. Breast-preservation therapy was less frequent for invasive lobular carcinoma. The 5-year overall survival and local disease-free survival rates for women treated with breast preservation were similar for invasive ductal carcinoma (84% overall survival; 97% disease-free survival) and invasive lobular carcinoma (87% overall survival; 98% disease-free survival).

CONCLUSIONS

Invasive lobular carcinoma presents with a similar age distribution, anatomic subsite, diameter, and grade as invasive ductal carcinoma. Breast preservation is selected less commonly for women who have invasive lobular carcinoma, but this choice of therapy does not compromise the disease-free or overall survival status of this group of patients.

Metabolic-cytokine responses to a second immunological challenge with LPS in mice with T. gondii infection

Injection of 10 cysts of Toxoplasma gondii (Me49 strain) into Swiss Webster mice results in 1) an acute phase of infection lasting for 2-3 wk, characterized by weight loss, and 2) a chronic phase in which surviving mice show either partial weight recovery (Gainers) or persistent, although stable, cachexia (Nongainers). In response to a second immunological stimulation with lipopolysaccharide (LPS) in the chronic phase of the infection, it is shown that 1) the increase in energy expenditure was more prolonged in both groups of infected mice than in controls, 2) the intensity and duration of hypophagia were also differently affected with Nongainers > Gainers > controls, and 3) the infected mice had higher serum levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-10 and a lower ratio of IL-10 to TNF-alpha than controls. In contrast, serum IL-4 increased to the same level in all three groups. Evaluation of the permeability of the blood-brain barrier by intravenous injection of Evans blue revealed a marked staining in the brain of only the infected Nongainers. Taken together, these results indicate that, in mice with chronic toxoplasmosis, a second nonspecific challenge (with LPS) exacerbates the hypophagic and hypermetabolic states, the latter being associated with hyperresponsiveness in TNF-alpha and IL-10 production. Furthermore, the greater exacerbation of the hypophagic state in mice showing persistent cachexia may be due to a preexisting higher permeability of the blood-brain barrier, which would allow a greater access of plasma-borne cytokines and/or other neuroimmunologically active substances to the central nervous system.

Reduced vascular beta-adrenergic receptors and catecholamine response in rats with lead induced hypertension

Beta-adrenergic receptor-mediated relaxation of blood vessels declines in lead induced hypertension although the mechanism is unknown. We have utilized the aorta of lead hypertensive rats to investigate this problem. In an effort to elucidate the mechanism responsible for this alteration we examined plasma catecholamine levels, vascular beta-adrenergic receptor density, and cyclic adenosine monophosphate (cAMP) production in lead hypertensive rats. The density of beta-adrenergic receptors was 41% lower in the blood vessels of lead hypertensive rats compared with control rats. The corresponding apparent Kd values were not significantly different between two groups. The plasma catecholamine level was significantly higher in lead hypertensive rats compared with controls (P < 0.001). Stimulation of the vascular beta-adrenoceptor resulted in significantly lower levels of cAMP in lead hypertensive rats compared with controls (P < 0.001). The present results suggest that there is reduced beta-adrenoceptor density and diminished cAMP accumulation in blood vessels from lead hypertensive rats. Plasma catecholamine may play a role in the diminished beta-adrenoceptor and responsiveness to cAMP-mediated vascular relaxation in lead exposure.

Change of cardiac beta-adrenoceptors in lead-exposed rats

The effect of lead on cardiac beta-adrenoceptors was studied. Wistar rats used in these trials were divided into seven groups of ten animals each (A-G). Of these, groups B was given drinking water containing 0.01% lead acetate, group C 0.05%, group D 0.1%, group E 0.5%, group F 1% and group G 2% for a period of 60 days. Group A was given pure water. A radioligand-binding assay fulfilling strict criteria of receptor affinity and density was used to quantify cardiac beta-adrenoceptors. Application of a trend test indicated that both blood and heart lead levels increased significantly from group A to group G (A < G), but that beta-adrenoceptor density decreased (G < A), whereas Kd did not vary among the seven groups. Linear regression analysis showed that decrease of cardiac beta-adrenergic receptor density was closely related to elevation of blood and heart lead levels. The results show that lead exposure results in a reduction of cardiac beta-adrenoceptor density.

Phylogenetic relationships of Salmonella typhi and Salmonella typhimurium based on 16S rRNA sequence analysis

The 16S rRNA gene sequences of Salmonella typhi and Salmonella typhimurium were amplified by PCR, cloned, and sequenced. These sequences were analyzed by comparison with reference organisms from the family Enterobacteriaceae. Both S. typhi and S. typhimurium belong to the gamma subdivision of the class Proteobacteria.

Optimal surgical treatment of invasive lobular carcinoma of the breast

BACKGROUND

The roles of breast conservation and surgical evaluation of the contralateral breast in the treatment of lobular carcinoma of the breast remain unclear. The aim of this study was to compare local recurrence, 5-year survival, and incidence of contralateral breast cancer in women with lobular carcinoma to that in women with infiltrating ductal carcinoma.

METHODS

Women with infiltrating ductal carcinoma (IDC) and invasive lobular breast carcinoma (ILC) diagnosed during the years 1984 to 1994 were identified through a statewide tumor registry. The women were divided into groups based on their histology and treatment (breast conservation or modified radical mastectomy). The incidences of contralateral breast cancer, local recurrence, and 5-year survival were compared within each histologic group and treatment category.

RESULTS

During the period 1984 to 1994, 4886 women were diagnosed with invasive lobular or ductal breast carcinoma. Of these, 316 (6.5%) had infiltrating lobular cancer. The 5-year survival rates were 68% and 71% for ILC and IDC, respectively (p = 0.5). The local recurrence rates were 2.8% and 4.3% for ILC treated with lumpectomy and axillary nodal dissection (LAND) and modified radical mastectomy (MRM), respectively, which were not significantly different from that obtained with IDC (LAND = 2.5%, MRM = 2.1%). The incidence of contralateral breast cancer during the period was 6.6% and 6.5% for ILC and IDC, respectively.

CONCLUSIONS

Invasive lobular carcinoma can be safely treated with breast conservation with no difference in local recurrence or survival. In the absence of a suspicious finding on clinical or radiologic examination, routine contralateral breast intervention is not recommended.

Altered energy balance and cytokine gene expression in a murine model of chronic infection with Toxoplasma gondii

The temporal pattern of changes in energy balance and cytokine mRNA expression in spleen and brain were examined in a mouse model of infection with Toxoplasma gondii. During days 1-7 postinfection, food intake was unaltered, but energy expenditure was significantly increased, and this was associated with elevated tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1, IL-5, and interferon (IFN)-gamma. The hypermetabolic state persisted during subsequent anorexia, whose onset coincided with elevated IL-2, and at the end of the acute phase of cachexia, the dual anorexic and hypermetabolic states were associated with the cytokines examined: TNF-alpha, IL-1 beta, IL-2, IL-4, IL-5, IL-6, IL-10, and IFN-gamma. In the chronic phase of the infection, the mice showed either partial weight recovery (gainers) or no weight regain (nongainers). The infected gainers, though still hypophagic, were no longer hypermetabolic, and their cytokine mRNA was no longer elevated, except for TNF-alpha and IL-10. In contrast, the infected nongainers continued to show both anoroxia and hypermetabolism, which were associated with elevations in all cytokines examined and particularly those of the TH2 profile (IL-4 and IL-5) and IL-6. Taken together, these studies reveal a distinct pattern of cytokine mRNA expression underlying 1) hypermetabolism vs. anorexia, 2) acute vs. chronic cachexia, and 3) stable weight loss vs. partial weight recovery.

The impact of histopathology on nodal metastases in minimal breast cancer

OBJECTIVE

To establish a model based on risk factor analysis to guide selective axillary lymph node dissection in patients with T1a and T1b breast cancers.

DESIGN

Retrospective review to determine histopathologic features and patient demographic profiles that may influence the incidence of nodal metastases.

SETTING

Primary care and referral centers in Rhode Island and Massachusetts.

PATIENTS

Women with invasive breast cancers with nodal status reported to the statewide tumor registry, the Hospital Association of Rhode Island, and the tumor registry at Baystate Medical Center, Springfield, Mass, between January 1984 and December 1995. There were 12030 patients with breast cancer reported; 2185 (18%) of these had tumors 1 cm or less in diameter.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

Axillary node metastases.

RESULTS

The nodal status of 377 patients with T1a tumors and 1808 patients with T1b tumors was studied. Seventy-five percent had axillary dissections, and 16% were found to have nodal metastases. Thirty-one percent (29/93) of patients younger than 40 years had positive nodes compared with 15% (241/1546) of older patients (P = .001). The T1a tumors had fewer metastases than the T1b tumors did (11% vs 17%; P = .02). Nuclear grade was available in 49% of cases. Nuclear grades 2 and 3 were associated with nodal involvement twice as often as grade 1 tumors were (P = .002). Patients with no poor prognostic factors had a 7% or less chance of nodal involvement, while patients with all 3 poor prognostic indicators had a 33.5% chance of nodal involvement.

CONCLUSIONS

Selective nodal dissection may be possible through risk factor analysis. Prospective registration of complete histopathologic information will allow more comprehensive analysis and may further enhance the selective treatment of patients with minimally invasive breast cancer.