Abstract 362: Repression of Smad3 by Stat3 and c-Ski/SnoN induces gefitinib resistance in lung adenocarcinoma

Cancer-associated inflammation develops resistance to the epidermal growth-factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in non-small cell lung cancers (NSCLCs) harboring oncogenic EGFR mutations. Stat3-mediated Interleukin (IL)-6 signaling and Smad-mediated transforming growth factor-β (TGF-β) signaling play crucial regulatory roles in cancer-associated inflammation. Here we show that Stat3 represses Smad3 in cooperation with c-Ski and SnoN, whereby renders gefitinib-sensitive HCC827 cells resistant. IL-6 signaling via phosphorylated Stat3 induced gefitinib resistance. By contrast, TGF-β upregulated gefitinib sensitivity. We found that IL-6 signaling via phosphorylated Stat3 repressed, whereas TGF-β upregulated the expression of Smad3 in HCC827 cells. Promoter analyses showed that Stat3 synergized with c-Ski/SnoN to repress Smad-induced transcription of the Smad3 gene. Smad3 induced apoptosis by upregulating pro-apoptotic genes such as Caspase 3 and downregulating anti-apoptotic genes such as Bcl2. Our results suggest that preventing IL-6/Stat3-induced loss of Smad3 can be a therapeutic strategy to prevent gefitinib resistance in NSCLCs with gefitinib-sensitive EGFR mutation.

Citation Format: Yojiro Makino, Jeong-Hwan Yoon, Eunjin Bae, Mitsuyasu Kato, Keiji Miyazawa, Tatsuo Ohira, Norihiko Ikeda, Masahiko Kuroda, Mizuko Mamura. Repression of Smad3 by Stat3 and c-Ski/SnoN induces gefitinib resistance in lung adenocarcinoma [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 362. doi:10.1158/1538-7445.AM2017-362

Abstract 4628: Selection of Smad2 for TGF-β to suppress dendritic cells by STAT3/c-Ski-induced repression of Smad3

The mechanisms how Smad-mediated transforming growth factor-β (TGF-β) signalling regulates dendritic cells (DCs) remain largely unknown, despite its crucial regulatory roles in the differentiation and activation of DCs. Here, we show that STAT3/c-Ski-induced downregulation of Smad3 during differentiation selects Smad2 as the specific TGF-β receptor-regulated Smad (R-Smad) to suppress the immunogenicity of DCs. Smad3 transcribed by unphosphorylated Smad2/3 prevented the progenitor cells from DC differentiation with repression of Flt3, IRF4 and STAT3. Repression of Smad3 by synergy of phosphorylated STAT3 and c-Ski was essential for DC differentiation. TGF-β suppressed DC activation via Smad2, hence DC-specific Smad2 deletion enhanced anti-lymphoma effector functions of cytotoxic T lymphocytes (CTLs) and type 1 helper T (Th1) cells in a mouse EL4 lymphoma model. Our findings reveal stepwise regulatory roles of R-Smads in DC regulation: Smad3 inhibits differentiation and Smad2 suppresses immunogenicity.

Citation Format: Jeong-Hwan Yoon, Eunjin Bae, Katsuko Sudo, Masakatsu Takanashi, Jin Soo Han, Seok Hee Park, Michael Weinstein, Susumu Nakae, Tadashi Yamashita, In-Kyu Lee, Ji Hyeon Ju, Takayuki Sumida, Masahiko Kuroda, Keiji Miyazawa, Mitsuyasu Kato, Mizuko Mamura. Selection of Smad2 for TGF-β to suppress dendritic cells by STAT3/c-Ski-induced repression of Smad3 [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 4628. doi:10.1158/1538-7445.AM2017-4628

Case report of 2 sudden deaths after surgery for bone fracture: Usefulness of immunohistochemical analysis of coronary artery for identifying acute myocardial infarction

RATIONALE

Death following orthopedic surgery has become rare, but does occur. Acute myocardial infarction (AMI) can be a cause of such death, but diagnosis of AMI is often challenging, even by autopsy.

PATIENT CONCERNS

We have recently experienced 2 cases of sudden death after bone fracture surgery, in which AMI and pulmonary thromboembolism were clinically suspected as causes of death. Case 1 was a 60-year-old male with a history of diabetes mellitus who died 7 days after surgery for Lisfranc dislocation fracture. Case 2 was a 75-year-old female who died several hours after surgery for proximal femur fracture.

DIAGNOSES

At autopsy, slight myocardial change suggestive of AMI, severe coronary stenosis, and pulmonary congestion were noted in case 1. No signs for AMI were observed, but diffuse fat emboli were identified in the pulmonary vasculature in Case 2. Thus, postmortem pathological diagnosis was AMI in case 1 and it was suggestive of fat emboli in case 2.

INTERVENTIONS

Immunohistochemical analysis of smooth muscle markers in the coronary artery was performed in both cases.

OUTCOMES

The positivity ratio of h-caldesmon to α-smooth muscle actin indicative of maturity of neointimal smooth muscle cells was preserved in case 2 but diminished in case 1, where coronary occlusion may have been caused via plaque rupture.

LESSONS

Immunostaining of smooth muscle markers in the coronary artery may serve as a supporting tool in establishing or disregarding AMI at autopsy.

Differences in subtype distribution between screen-detected and symptomatic invasive breast cancer and their impact on survival

PURPOSE

Stage shift is considered a major reason for more favorable outcomes in patients with screen-detected breast cancer. However, even after adjusting for clinical stage, unresolved issues concerning the reasons for a survival benefit associated with screening programs remain. This study aims to evaluate differences in subtype distribution and outcomes among patients with screen-detected and symptomatic invasive breast cancer and assess whether variations in subtype distribution could explain differences in prognosis.

METHODS

Survival analysis was performed to estimate the likelihood of distant recurrence and death in 1132 patients. Subtypes were defined as luminal A [estrogen receptor (ER)+ and/or progesterone receptor (PR)+, human epidermal growth factor receptor 2 (HER2)-, and Ki67 low], luminal B (HER2-) (ER+ and/or PR+, HER2-, and Ki67 high), luminal B (HER2+) (ER+ and/or PR+ and HER2+), HER2 overexpressing (ER-, PR-, and HER2+), and triple negative (ER-, PR-, and HER2-).

RESULTS

Screen-detected cancers had favorable clinicopathological characteristics, such as smaller tumor size and a lower frequency of lymph node involvement. Women with screen-detected cancers had a survival advantage. Subtype distribution differed significantly among women with screen-detected and symptomatic cancer. Screen-detected cancers were more likely to be luminal A and less likely to be HER2 overexpressing or triple negative cancer compared with symptomatic cancers (luminal A 61.3 vs. 44.2%, HER2 overexpressing 4.0 vs. 8.0%, triple negative 8.0 vs. 15.9%). Node status, mode of detection, and subtype were independent prognostic factors in the multivariate analysis.

CONCLUSIONS

Differences in subtype distribution between screen-detected and symptomatic cancer could partially explain differences in outcomes.

Relationship between Time from Full Pulpotomy to Definitive Diagnosis of Vertical Root Fracture and Patient Age

The goal of this study was to investigate length of time between full pulpotomy and a definitive diagnosis of vertical root fracture (VRF), as well as the age at which this was made. The participants comprised 63 dental patients (40 men and 23 women) with a mean age of 65.7±10.4 years in whom a definitive diagnosis of VRF had been made between July 2013 and June 2015, and who had also undergone a full pulpotomy. The data on all these cases were obtained from 22 dental clinics belonging to a clinical study group. The mean duration between a full pulpotomy and a definitive diagnosis of VRF was 141.0±88.9 months. The results showed no differences in terms of sex, mandible/maxilla, or tooth type. No relationship was observed between age at which the diagnosis was made and length of time between full pulpotomy and diagnosis (Pearson correlation coefficient = 0.162) (p>0.05). Most diagnoses of VRF were made in patients aged over 50 years, irrespective of length of time between full pulpotomy and the diagnosis. These results suggest that age is a stronger indicator of VRF than length of time between full pulpotomy and a definitive diagnosis.

Pathological Diagnosis of Gastric Cancers with a Novel Computerized Analysis System

Background:

Recent studies of molecular biology have provided great advances for diagnostic molecular pathology. Automated diagnostic systems with computerized scanning for sampled cells in fluids or smears are now widely utilized. Automated analysis of tissue sections is, however, very difficult because they exhibit a complex mixture of overlapping malignant tumor cells, benign host-derived cells, and extracellular materials. Thus, traditional histological diagnosis is still the most powerful method for diagnosis of diseases.

Methods:

We have developed a novel computer-assisted pathology system for rapid, automated histological analysis of hematoxylin and eosin (H and E)-stained sections. It is a multistage recognition system patterned after methods that human pathologists use for diagnosis but harnessing machine learning and image analysis. The system first analyzes an entire H and E-stained section (tissue) at low resolution to search suspicious areas for cancer and then the selected areas are analyzed at high resolution to confirm the initial suspicion.

Results:

After training the pathology system with gastric tissues samples, we examined its performance using other 1905 gastric tissues. The system's accuracy in detecting malignancies was shown to be almost equal to that of conventional diagnosis by expert pathologists.

Conclusions:

Our novel computerized analysis system provides a support for histological diagnosis, which is useful for screening and quality control. We consider that it could be extended to be applicable to many other carcinomas after learning normal and malignant forms of various tissues. Furthermore, we expect it to contribute to the development of more objective grading systems, immunohistochemical staining systems, and fluorescent-stained image analysis systems.

Repression of Smad3 by Stat3 and c-Ski/SnoN induces gefitinib resistance in lung adenocarcinoma

Cancer-associated inflammation develops resistance to the epidermal growth-factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in non-small cell lung cancers (NSCLCs) harboring oncogenic EGFR mutations. Stat3-mediated interleukin (IL)-6 signaling and Smad-mediated transforming growth factor-β (TGF-β) signaling pathways play crucial regulatory roles in cancer-associated inflammation. However, mechanisms how these pathways regulate sensitivity and resistance to EGFR-TKI in NSCLCs remain largely undetermined. Here we show that signal transducer and activator of transcription (Stat)3 represses Smad3 in synergy with the potent negative regulators of TGF-β signaling, c-Ski and SnoN, whereby renders gefitinib-sensitive HCC827 cells resistant. We found that IL-6 signaling via phosphorylated Stat3 induced gefitinib resistance as repressing transcription of Smad3, whereas TGF-β enhanced gefitinib sensitivity as activating transcription of Smad3 in HCC827 cells with gefitinib-sensitizing EGFR mutation. Promoter analyses showed that Stat3 synergized with c-Ski/SnoN to repress Smad2/3/4-induced transcription of the Smad3 gene. Smad3 was found to be an apoptosis inducer, which upregulated pro-apoptotic genes such as caspase-3 and downregulated anti-apoptotic genes such as Bcl-2. Our results suggest that derepression of Smad3 can be a therapeutic strategy to prevent gefitinib-resistance in NSCLCs with gefitinib-sensitizing EGFR mutation.

Case report of multiple pustules of the bilateral lower limbs caused by a granulocyte colony-stimulating factor-producing solid pseudopapillary tumour of the pancreas

Here we report a rare case of neutrophilic dermatoses related to a granulocyte colony-stimulating factor (G-CSF)-producing solid pseudopapillary tumour (SPT). The patient was a 39-year-old woman presenting with scattered pustules and crusts of the palms, heels and thighs and plaques of the bilateral lower legs. The skin biopsy revealed dense neutrophil infiltration in the epidermis to the dermis. A pancreatic head tumour was detected using computed tomography. A pathological examination of the resected specimen suggested an SPT. As the skin eruption promptly disappeared after SPT resection, we hypothesized that SPT secretes growth factors including epidermal growth factor (EGF) and G-CSF. The SPT cells stained positive for both EGF and G-CSF tumour cells. The serum levels of interleukin (IL)-6 and IL-10 and tumour necrosis factor-α were within normal limits before and after the SPT resection. In contrast, the serum IL-8, EGF and G-CSF levels decreased after the SPT resection. This is a rare case of neutrophilic dermatoses related to a G-CSF-producing SPT. The present case suggests that physicians should be aware that a G-CSF-producing tumour is a differential diagnosis to consider in patients with unusual aseptic pustulosis.

Control of HCV Replication With iMIRs, a Novel Anti-RNAi Agent

MicroRNAs (miRNAs) serve important roles in regulating various physiological activities through RNA interference (RNAi). miR-122 is an important mediator of RNAi that is known to control hepatitis C virus (HCV) replication and is being investigated in clinical trials as a target for anti-HCV therapy. In this study, we developed novel oligonucleotides containing non-nucleotide residues, termed iMIRs, and tested their abilities to inhibit miR-122 function. We compared the inhibitory effects of iMIRs and locked nucleic acids (LNAs) on HCV replication in OR6 cells, which contained full-length HCV (genotype 1b) and a luciferase reporter gene. We found that RNA-type iMIRs with bulge-type, imperfect complementarity with respect to miR-122 were 10-fold more effective than LNAs in inhibiting HCV replication and functioned in a dose-dependent manner. Moreover, iMIR treatment of OR6 cells reduced HCV replication without inducing interferon responses or cellular toxicity. Based on these results, we suggest that iMIRs can inhibit HCV replication more effectively than LNAs and are therefore promising as novel antiviral agents.

Cardiac myofibroblast engulfment of dead cells facilitates recovery after myocardial infarction

Myocardial infarction (MI) results in the generation of dead cells in the infarcted area. These cells are swiftly removed by phagocytes to minimize inflammation and limit expansion of the damaged area. However, the types of cells and molecules responsible for the engulfment of dead cells in the infarcted area remain largely unknown. In this study, we demonstrated that cardiac myofibroblasts, which execute tissue fibrosis by producing extracellular matrix proteins, efficiently engulf dead cells. Furthermore, we identified a population of cardiac myofibroblasts that appears in the heart after MI in humans and mice. We found that these cardiac myofibroblasts secrete milk fat globule-epidermal growth factor 8 (MFG-E8), which promotes apoptotic engulfment, and determined that serum response factor is important for MFG-E8 production in myofibroblasts. Following MFG-E8-mediated engulfment of apoptotic cells, myofibroblasts acquired antiinflammatory properties. MFG-E8 deficiency in mice led to the accumulation of unengulfed dead cells after MI, resulting in exacerbated inflammatory responses and a substantial decrease in survival. Moreover, MFG-E8 administration into infarcted hearts restored cardiac function and morphology. MFG-E8-producing myofibroblasts mainly originated from resident cardiac fibroblasts and cells that underwent endothelial-mesenchymal transition in the heart. Together, our results reveal previously unrecognized roles of myofibroblasts in regulating apoptotic engulfment and a fundamental importance of these cells in recovery from MI.

An improved Red/ET recombineering system and mouse ES cells culture conditions for the generation of targeted mutant mice

Targeted mutant mice generated on a C57BL/6 background are powerful tools for analysis of the biological functions of genes, and gene targeting technologies using mouse embryonic stem (ES) cells have been used to generate such mice. Recently, a bacterial artificial chromosome (BAC) recombineering system was established for the construction of targeting vectors. However, gene retrieval from BACs for the generation of gene targeting vectors using this system remains difficult. Even when construction of a gene targeting vector is successful, the efficiency of production of targeted mutant mice from ES cells derived from C57BL/6 mice are poor. Therefore, in this study, we first improved the strategy for the retrieval of genes from BACs and their transfer into a DT-A plasmid, for the generation of gene targeting vectors using the BAC recombineering system. Then, we attempted to generate targeted mutant mice from ES cell lines derived from C57BL/6 mice, by culturing in serum-free medium. In conclusion, we established an improved strategy for the efficient generation of targeted mutant mice on a C57BL/6 background, which are useful for the in vivo analysis of gene functions and regulation.

A novel method for morphological pleomorphism and heterogeneity quantitative measurement: Named cell feature level co-occurrence matrix

Background:

Recent developments in molecular pathology and genetic/epigenetic analysis of cancer tissue have resulted in a marked increase in objective and measurable data. In comparison, the traditional morphological analysis approach to pathology diagnosis, which can connect these molecular data and clinical diagnosis, is still mostly subjective. Even though the advent and popularization of digital pathology has provided a boost to computer-aided diagnosis, some important pathological concepts still remain largely non-quantitative and their associated data measurements depend on the pathologist's sense and experience. Such features include pleomorphism and heterogeneity.

Methods and Results:

In this paper, we propose a method for the objective measurement of pleomorphism and heterogeneity, using the cell-level co-occurrence matrix. Our method is based on the widely used Gray-level co-occurrence matrix (GLCM), where relations between neighboring pixel intensity levels are captured into a co-occurrence matrix, followed by the application of analysis functions such as Haralick features. In the pathological tissue image, through image processing techniques, each nucleus can be measured and each nucleus has its own measureable features like nucleus size, roundness, contour length, intra-nucleus texture data (GLCM is one of the methods). In GLCM each nucleus in the tissue image corresponds to one pixel. In this approach the most important point is how to define the neighborhood of each nucleus. We define three types of neighborhoods of a nucleus, then create the co-occurrence matrix and apply Haralick feature functions. In each image pleomorphism and heterogeneity are then determined quantitatively. For our method, one pixel corresponds to one nucleus feature, and we therefore named our method Cell Feature Level Co-occurrence Matrix (CFLCM). We tested this method for several nucleus features.

Conclusion:

CFLCM is showed as a useful quantitative method for pleomorphism and heterogeneity on histopathological image analysis.

Development of Novel Small Hairpin RNAs That do not Require Processing by Dicer or AGO2

The innate cytokine response to nucleic acid is the most challenging problem confronting the practical use of nucleic acid medicine. The degree of stimulation of the innate cytokine response strongly depends on the length of the nucleic acid. In this study, we developed a 30-nucleotide single-strand RNA, termed "guide hairpin RNA (ghRNA, ghR)", that has a physiological function similar to that of miRNA and siRNA. The ghR caused no innate cytokine response either in vitro or in vivo. In addition, its structure does not contain a passenger strand seed sequence, reducing the unwanted gene repression relative to existing short RNA reagents. Systemic and local injection of ghR-form miR-34a (ghR-34a) suppressed tumor growth in a mouse model of RAS-induced lung cancer. Furthermore, Dicer and AGO2 are not required for ghR-34a function. This novel RNA interference (RNAi) technology may provide a novel, safe, and effective nucleic acid drug platform that will increase the clinical usefulness of nucleic acid therapy.

Synovial Sarcoma With a Predominant Epithelial Component

A case of synovial sarcoma of the lower leg in a 59-year-old woman with a predomi nant epithelial component is reported. Histologically, the tumor showed a well-devel oped epithelial component with a sheet-like and cribriform pattern with a sparsely distributed spindle cell component. Immunohistochemically, the epithelial component was positive for cytokeratins and epithelial membrane antigen, while the spindle cell component was positive for cytokeratins, epithelial membrane antigen, and vimentin. The epithelial component of synovial sarcoma is indistinguishable from carcinoma morphologically and immunohistochemically, therefore the presence of a biphasic pattern, even with a paucity of spindle cell component, is a crucial finding to establish a diagnosis of synovial sarcoma. The recognition and subclassification of this type of synovial sarcoma is important in arriving at a correct prognosis. Int J Surg Pathol 1(4): 261-268, 1994

MiR-29a Assists in Preventing the Activation of Human Stellate Cells and Promotes Recovery From Liver Fibrosis in Mice

The microRNA-29 (miR-29) family is known to suppress the activation of hepatic stellate cells (HSCs) and reversibly control liver fibrosis; however, the mechanism of how miR-29a controls liver fibrosis remains largely unknown. This study was conducted to clarify the mechanism of anti-fibrotic effect of miR-29a and to explore if miR-29a is a promising candidate for nucleic acid medicine against liver fibrosis. Two liver fibrosis murine models (carbon tetrachloride or thioacetamide) were used. MiR-29a mixed with atelocollagen was systemically administered. Hepatic fibrosis was evaluated by histological analysis and the expression levels of fibrosis-related genes. We observed that miR-29a treatment dramatically accelerated the reversion of liver fibrosis in vivo. Additionally, miR-29a regulated the mRNA expression of collagen type I alpha 1 (COL1A1) and platelet-derived growth factor C (PDGFC). We also noted that miR-29a significantly suppressed COL1A1 mRNA expression and cell viability and significantly increased caspase-9 activity (P < 0.05) in LX-2 cells. Pretreatment of miR-29a inhibited activation of LX-2 cell by transforming growth factor beta treatment. MiR-29a exhibited anti-fibrotic effect without cell toxicity in vivo and directly suppressed the expression of PDGF-related genes as well as COL1A1 and induced apoptosis of LX-2 cells. MiR-29a is a promising nucleic acid inhibitor to target liver fibrosis.