Abstract PD1-04: Nuclear localization of intracellular domain of LDL receptor-related protein 1B predicts poor outcome in breast cancer; putative relation to NEAT1 mediated mammary gland carcinogenesis

Background:Low-density lipoprotein receptor-related protein 1B(LRP1B) is thought to have a pleiotropic biological function. Notably, intracellular domain of LRP1B is released and transported to nucleus in a γ-secretase dependent fashion; however, pathological property, which is driven by nuclear transport of intracellular domain of LRP1B is largely unclear. In this study, we aimed to unravel the pathological significance of nuclear localization of intracellular domain of LRP1B in mammary gland carcinogenesis. Aims: We examine the clinical significance of LRP1B for breast cancer and we clarify mechanism of nuclear localization of LRP1B in invasive ductal carcinoma. Methods: Immunohistochemical staining using newly generated antibodies to intracellular domain of LRP1B was used to determine LRP1B expression in 92 invasive ductal carcinomas of the breast. The clinicopathological significance including prognosis value was statistically analyzed. Doxycycline dependent nuclear expression of intracellular domain of LAP1B was established in cultured breast cancer cells. Subsequently, a series of in vitro experiments were performed to explore the role of nuclear localized intracellular domain of LRP1B in cultured breast cancer cells. Comprehensive microarray-based analysis followed by quantitative RT-PCR and chromatin immunoprecipitation assay was performed to know the altered molecular signature induced by nuclear localized intracellular domain of LRP1B. Results: Non-tumorous mammary duct epithelial cells did not exhibit LRP1B staining, whereas different degrees of LRP1B immunoreactivity were observed in 75 of 92 invasive ductal carcinoma of the breast. LRP1B immunoreactivity was found in surface membrane and cytoplasm of 60 of 92(65.2%) invasive ductal carcinoma cells, whereas it was detected in nucleus of 15 of 92(16.3%)cancer cells. Interestingly, nuclear LRP1B immunoreactivity was significantly associated with poor prognosis of the patients, especially with luminal A type breast cancers. Notably, nuclear localized intracellular domain of LRP1B significantly related to status of nodal metastasis in luminal A type breast cancers. Enforced nuclear expression significantly increased Matrigel invasion activity in MCF-7 luminal A breast cancer cells without affecting cell growth. Notably, nuclear expression of intracellular domain of LRP1B decreased transcription of LRP1B. Comprehensive microarray-based analysis demonstrated that nuclear expression of intracellular domain of LRP1B significantly increased the expression of long non-coding RNA nuclear paraspeckle assembly transcript1(NEAT1), which facilitates breast cancer invasion with poor survival. Conclusions: Present findings indicated that nuclear localized intracellular domain of LTP1B promoted breast cancer progression with a poor prognostic value, possible through NEAT1 pathway. Nuclear transport of intracellular domain of LRP1B could be a therapeutic target for breast cancer patients.

Citation Format: Asano Y, Futamura M, Takeuchi T, Yoshida K. Nuclear localization of intracellular domain of LDL receptor-related protein 1B predicts poor outcome in breast cancer; putative relation to NEAT1 mediated mammary gland carcinogenesis [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 PD1-04.

Prognostic value of quality-of-life scores in patients with breast cancer undergoing preoperative chemotherapy

Background

Recently, evaluation of quality of life (QOL) has been recognized as a significant outcome measure in the treatment of several cancers. In this study, the Anti-Cancer Drugs-Breast (ACD-B) QOL score was used to assess disease-specific survival in women with breast cancer undergoing preoperative chemotherapy (POC).

Methods

QOL-ACD-B scores were evaluated before and after POC. The cut-off value of QOL-ACD-B contributing to events such as relapse or death was calculated by receiver operating characteristic (ROC) curve analysis.

Results

In 300 women with breast cancer treated with POC, QOL was significantly reduced (P < 0·001). A high QOL-ACD-B score before POC was an independent factor in the multivariable analysis of overall survival (hazard ratio 0·26, 95 per cent c.i. 0·04 to 0·96).

Conclusion

Evaluation by QOL-ACD-B before POC may be useful to predict the prognosis of patients with breast cancer undergoing POC.

Progressive reduction of serum complement levels: a risk factor for relapse in patients with hypocomplementemia in systemic lupus erythematosus

Objective

Serologically active clinically quiescent (SACQ)-SLE is a subtype of systemic lupus erythematosus (SLE); most SACQ-SLE patients relapse. Although complement and/or anti-dsDNA level fluctuations during SACQ status are reportedly not useful for predicting relapse, they might be useful in specific clinical settings. We aimed to assess the correlation between future relapse and progressive reductions in serum complement levels following remission in patients with hypocomplementemia .

Methods

We retrospectively reviewed patients aged ≥15 years who were treated with ≥20 mg/day of prednisolone for remission induction. After achieving remission, the patients treated with prednisolone tapered to ≤15 mg/day without relapse and followed by hypocomplementemia (first hypocomplementemia point) were analyzed. The primary outcome was the relapse during the first 24 months.

Results

Seventy-six patients were enrolled; 31 (40.8%) relapsed. A ≥10% reduction after the first hypocomplementemia point in serum C3, C4, and CH50 levels was found in 10, 21, and 16 patients, respectively. Hazard ratios (95% confidence intervals) for relapse were 2.32 (0.92–5.12) for serum C3 levels and 2.46 (1.18–5.01) for serum C4 levels. Progressive reductions in serum C3 and C4 levels had relatively high specificity (93.3% and 82.2%) but limited sensitivity (22.6% and 41.9%) for predicting relapse. However, simultaneous progressive reduction in C3 levels and increase in anti-dsDNA antibody levels had the highest specificity (97.8%), and simultaneous progressive reduction in C4 levels or increase in anti-dsDNA antibody levels had the highest sensitivity (71.0%).

Conclusion

Simultaneous progressive reductions in complement levels and increases in anti-dsDNA antibody levels may indicate future relapse SACQ-SLE patients.

Availability of a Magnetic Method for Hepatocyte Transplantation

INTRODUCTION

Hepatocyte transplantation is a promising alternate for the treatment of hepatic diseases. Hypothermic preservation of isolated human hepatocytes is potentially a simple and convenient strategy to provide on-demand hepatocytes in the quantity sufficient and the quality required for biotherapy. Isolated fresh hepatocytes include damaged cells that are also early apoptotic cells, which is not ideal for hepatocyte transplantation. However, this does not reflect cell viability, although it is considered that it adversely affects cell survival after transplantation. We aimed to harvest these hepatocytes and filter the apoptotic cells using a magnetic method to provide a transplantation source.

MATERIALS AND METHODS

Rat hepatocytes were isolated from caudate lobes using manual enzymatic perfusion. The hepatocyte yield was 5.3 ± 0.66 × 10⁹ cells/g of liver tissue, with a viability of 82.3 ± 3.5%. Two samples of hepatocytes were freshly isolated, one using the magnetic method, and the other without. The magnetic method was performed using DynaMag-15 Magnet, and Annexin V Antibody was used on the early apoptotic cells. We evaluated the viability and plate efficiency of the cells after 24 hours at 37°C. Hepatocytes were isolated using cell separation method, and 30 × 10⁶ cells were mixed with 1.0 mL of Dulbecco's Modified Eagle's Medium (DMEM) and directly injected into the spleen of Lewis rats (150-250 g) using 24-gauge needles. Blood samples were collected on days 0, 3, 7, and 14, and the blood albumin level was measured using enzyme-linked immunosorbent assay (ELISA):G1, control (medium injection); G2, fresh hepatocyte transplant using the magnetic method; and G3, fresh hepatocyte transplant without the magnetic method.

RESULTS

The viability was 84.9 ± 2% for fresh hepatocytes and 80.7 ± 1.2% for hepatocytes isolated using the magnetic method. The magnetic method does not damage the cells (73.5 ± 2% vs 35.2 ± 2% after 24 hours), preserving hepatocyte. The albumin level accepted significantly increased in the magnet-treated group compared with the nonmagnet group. Simultaneously, the spleen in which these hepatocytes were transplanted could be used to observe the hepatocytes; the cells were transplanted 14 days later, and the magnet-treated group had significantly higher levels of hepatocytes than the nonmagnet group.

CONCLUSION

We developed an effective technique for hepatocyte isolation for short-term preservation. As a result, we believe that transplantation not only improves the cell transplantation effect but also allows the cells to be stored efficiently using the magnetic method. These results demonstrate the usefulness of hepatocyte hypothermic preservation for cell transplantation.

Sphingosine-1-phosphate receptor-2 facilitates pulmonary fibrosis through potentiating IL-13 pathway in macrophages

Idiopathic pulmonary fibrosis is a devastating disease with poor prognosis. The pathogenic role of the lysophospholipid mediator sphingosine-1-phosphate and its receptor S1PR2 in lung fibrosis is unknown. We show here that genetic deletion of S1pr2 strikingly attenuated lung fibrosis induced by repeated injections of bleomycin in mice. We observed by using S1pr2^LacZ/+ mice that S1PR2 was expressed in alveolar macrophages, vascular endothelial cells and alveolar epithelial cells in the lung and that S1PR2-expressing cells accumulated in the fibrotic legions. Bone marrow chimera experiments suggested that S1PR2 in bone marrow–derived cells contributes to the development of lung fibrosis. Depletion of macrophages greatly attenuated lung fibrosis. Bleomycin administration stimulated the mRNA expression of the profibrotic cytokines IL-13 and IL-4 and the M2 markers including arginase 1, Fizz1/Retnla, Ccl17 and Ccl24 in cells collected from broncho-alveolar lavage fluids (BALF), and S1pr2 deletion markedly diminished the stimulated expression of these genes. BALF cells from bleomycin–administered wild-type mice showed a marked increase in phosphorylation of STAT6, a transcription factor which is activated downstream of IL-13, compared with saline–administered wild-type mice. Interestingly, in bleomycin–administered S1pr2^-/- mice, STAT6 phosphorylation in BALF cells was substantially diminished compared with wild-type mice. Finally, pharmacological S1PR2 blockade in S1pr2^+/+ mice alleviated bleomycin–induced lung fibrosis. Thus, S1PR2 facilitates lung fibrosis through the mechanisms involving augmentation of IL-13 expression and its signaling in BALF cells, and represents a novel target for treating lung fibrosis.

Interleukin-25 is involved in cutaneous T-cell lymphoma progression by establishing a T helper 2-dominant microenvironment

BACKGROUND

Interleukin (IL)-25 is a member of the IL-17 family, which can promote and augment T-helper (Th) type 2 responses. The expression of IL-25 and its cognate receptor, IL-25 receptor (IL-25R), is upregulated and correlated with disease activity in Th2-associated diseases.

OBJECTIVES

To examine the expression and function of IL-25 in cutaneous T-cell lymphoma (CTCL).

METHODS

Expression and location of IL-25 in lesional skin was investigated with immunohistochemistry. The effect of various cytokines on IL-25 production from normal human epidermal keratinocytes was assessed by quantitative reverse-transcription real-time polymerase chain reaction. Serum IL-25 levels were measured by enzyme-linked immunosorbent assay. The direct effect of IL-25 on tumour cells was also examined using CTCL cell lines and peripheral blood mononuclear cells in patients with Sézary syndrome.

RESULTS

IL-25 expression was increased in epidermal keratinocytes in lesional skin of CTCL. Th2 cytokines, IL-4 and IL-13, and periostin induced IL-25 expression by normal human epidermal keratinocytes. Serum IL-25 levels were increased in patients with advanced CTCL and correlated with serum lactate dehydrogenase levels. MyLa cells expressed IL-25R and its expression was augmented by stimulation with IL-25. IL-25 enhanced IL-13 production from MyLa cells via phosphorylation of signal transducer and activator of transcription 6. Peripheral blood mononuclear cells from one patient with Sézary syndrome expressed IL-25R and showed increase of IL-13 production by IL-25.

CONCLUSIONS

Th2 cytokines highly expressed in CTCL lesional skin induce IL-25 production by epidermal keratinocytes, which may, in turn, lead to formation of a Th2-dominant microenvironment through the direct induction of IL-13 by tumour cells.