Aldolase A promotes cervical cancer cell radioresistance by regulating the glycolysis and DNA damage after irradiation

Radioresistance is the major obstacle that affects the efficacy of radiotherapy which is an important treatment for cervical cancer. By analyzing the databases, we found that aldolase A (ALDOA), which is a key enzyme in metabolic reprogramming, has a higher expression in cervical cancer patients and is associated with poor prognosis. We detected the expression of ALDOA in the constructed cervical cancer radioresistance (RR) cells by repetitive irradiation and found that it was upregulated compared to the control cells. Functional assays were conducted and the results showed that the knockdown of ALDOA in cervical cancer RR cells inhibited the proliferation, migration, and clonogenic abilities by regulating the cell glycolysis. In addition, downregulation of ALDOA enhanced radiation-induced apoptosis and DNA damage by causing G2/M phase arrest and further promoted radiosensitivity of cervical cancer cells. The functions of ALDOA in regulating tumor radiosensitivity were also verified by the mouse tumor transplantation model in vivo. Therefore, our study provides new insights into the functions of ALDOA in regulating the efficacy of radiotherapy and indicates that ALDOA might be a promising target for enhancing radiosensitivity in treating cervical cancer patients.

Hypoxic tumor cell-derived small extracellular vesicle miR-152-3p promotes cervical cancer radioresistance through KLF15 protein

BACKGROUND

Radiotherapy is widely used in treating cervical cancer patients, however, radioresistance unavoidably occurs and seriously affects the treatment effect. It is well known that hypoxia plays an important role in promoting radioresistance in tumor microenvironment, yet our understanding of the effect of small extracellular vesicles miRNA on cervical cancer radiosensitivity in hypoxic environment is still limited.

METHODS

Small extracellular vesicles extracted from hypoxic and normoxic cultured cervical cancer cells were evaluated for their effects on radioresistance. miR-152-3p was found to be a potential effector in hypoxia-derived extracellular vesicles by searching the GEO database. Its downstream substrate was confirmed by double luciferase report, which was KLF15. The role of miR-152-3p and KLF15 in regulating cervical cancer radioresistance was detected by cell activity assays. The findings were confirmed in vivo by animal models. The expression of miR-152-3p was quantified by qRT-PCR and its prognostic significance was evaluated.

RESULTS

Hypoxic environment promoted the secretion of small extracellular vesicles, and reduced the apoptosis and DNA damage caused by radiation, accompanied by increased expression of small extracellular vesicles miR-152-3p from hypoxic cervical cancer cells. Furthermore, small extracellular vesicles miR-152-3p promoted Hela xenograft growth and reduced the radiosensitivity vivo. Mechanism studies revealed that KLF15 protein was the downstream target of miR-152-3p in regulating radioresistance.

CONCLUSION

Our findings suggest that small extracellular vesicles miR-152-3p affects the therapeutic effect of radiotherapy and holds potential as a biomarker or therapeutic target for cervical cancer prognosis and improving radiotherapy.

Treatment strategies for intrauterine adhesion: focus on the exosomes and hydrogels

Intrauterine adhesion (IUA), also referred to as Asherman Syndrome (AS), results from uterine trauma in both pregnant and nonpregnant women. The IUA damages the endometrial bottom layer, causing partial or complete occlusion of the uterine cavity. This leads to irregular menstruation, infertility, or repeated abortions. Transcervical adhesion electroreception (TCRA) is frequently used to treat IUA, which greatly lowers the prevalence of adhesions and increases pregnancy rates. Although surgery aims to disentangle the adhesive tissue, it can exacerbate the development of IUA when the degree of adhesion is severer. Therefore, it is critical to develop innovative therapeutic approaches for the prevention of IUA. Endometrial fibrosis is the essence of IUA, and studies have found that the use of different types of mesenchymal stem cells (MSCs) can reduce the risk of endometrial fibrosis and increase the possibility of pregnancy. Recent research has suggested that exosomes derived from MSCs can overcome the limitations of MSCs, such as immunogenicity and tumorigenicity risks, thereby providing new directions for IUA treatment. Moreover, the hydrogel drug delivery system can significantly ameliorate the recurrence rate of adhesions and the intrauterine pregnancy rate of patients, and its potential mechanism in the treatment of IUA has also been studied. It has been shown that the combination of two or more therapeutic schemes has broader application prospects; therefore, this article reviews the pathophysiology of IUA and current treatment strategies, focusing on exosomes combined with hydrogels in the treatment of IUA. Although the use of exosomes and hydrogels has certain challenges in treating IUA, they still provide new promising directions in this field.

Peptide-functionalized therapeutic nanoplatform for treatment orthotopic triple negative breast cancer and bone metastasis

Epidermal Growth Factor Receptor (EGFR) is a promising therapeutic target for triple-negative breast cancer (TNBC). Recently, specific EGFR-targeting peptide GE11-based delivery nano-system shows excellent potential because of its chemical versatility and good targeting ability. However, no further research focusing on the downstream of EGFR after binding with GE11 was explored. Hence, we tailor-designed a self-assembled nanoplatform named GENP using amphiphilic molecule of stearic acid-modified GE11. After loading doxorubicin (DOX), the resulted nanoplatform GENP@DOX demonstrated high loading efficiency and sustainable drug release. Importantly, our findings proved that GENP alone significantly suppressed the proliferation of MDA-MB-231 cells via EGFR-downstream PI3K/AKT signaling pathways, contributing to the synergistic treatment with its DOX release. Further work illustrated remarkable therapeutic efficacy both in orthotopic TNBC and its bone metastasis models with minimal biotoxicity. Together, the results highlight that our GENP-functionalized nanoplatform is a promising strategy for the synergistic therapeutic efficacy targeting EGFR-overexpressed cancer.

S100A4-dependent glycolysis promotes lymphatic vessel sprouting in tumor

Tumor-induced lymphangiogenesis promotes the formation of new lymphatic vessels, contributing to lymph nodes (LNs) metastasis of tumor cells in both mice and humans. Vessel sprouting appears to be a critical step in this process. However, how lymphatic vessels sprout during tumor lymphangiogenesis is not well-established. Here, we report that S100A4 expressed in lymphatic endothelial cells (LECs) promotes lymphatic vessel sprouting in a growing tumor by regulating glycolysis. In mice, the loss of S100A4 in a whole body (S100A4^-/-), or specifically in LECs (S100A4^ΔLYVE1) leads to impaired tumor lymphangiogenesis and disrupted metastasis of tumor cells to sentinel LNs. Using a 3D spheroid sprouting assay, we found that S100A4 in LECs was required for the lymphatic vessel sprouting. Further investigations revealed that S100A4 was essential for the position and motility of tip cells, where it activated AMPK-dependent glycolysis during lymphatic sprouting. In addition, the expression of S100A4 in LECs was upregulated under hypoxic conditions. These results suggest that S100A4 is a novel regulator of tumor-induced lymphangiogenesis. Targeting S100A4 in LECs may be a potential therapeutic strategy for lymphatic tumor metastasis.

Characterization of fecal microbiota in cervical cancer patients associated with tumor stage and prognosis

Cervical cancer (CC) is the fourth most frequent malignancy among women worldwide, and its prevention and treatment are evolving rapidly. The gut microbiota has been reported to play a crucial role both in the preservation of homeostasis and the development of cervical cancer. In this study, we collected fecal samples to investigate the microbial signatures in cervical cancer patients compared with healthy controls using 16S rRNA sequencing analysis and metagenomic next-generation sequencing (mNGS) testing. Our findings demonstrated a substantial difference in the gut microbiota composition of cervical cancer patients and healthy controls. The disease and stage were most significantly negatively correlated with Ruminococcus 2, which might be considered a potential clinically relevant biomarker. Functions of differential microbiomes were also analyzed, indicating significant differences in metabolisms and biosynthesis between the two groups. These findings demonstrate that patients with cervical cancer have certain species of gut microbiota that are exclusive to them and particular species have the potential to be used in the prognosis of cervical cancer.

Recent progress of the tumor microenvironmental metabolism in cervical cancer radioresistance

Radiotherapy is widely used as an indispensable treatment option for cervical cancer patients. However, radioresistance always occurs and has become a big obstacle to treatment efficacy. The reason for radioresistance is mainly attributed to the high repair ability of tumor cells that overcome the DNA damage caused by radiotherapy, and the increased self-healing ability of cancer stem cells (CSCs). Accumulating findings have demonstrated that the tumor microenvironment (TME) is closely related to cervical cancer radioresistance in many aspects, especially in the metabolic processes. In this review, we discuss radiotherapy in cervical cancer radioresistance, and focus on recent research progress of the TME metabolism that affects radioresistance in cervical cancer. Understanding the mechanism of metabolism in cervical cancer radioresistance may help identify useful therapeutic targets for developing novel therapy, overcome radioresistance and improve the efficacy of radiotherapy in clinics and quality of life of patients.

Recent advances of non-coding RNAs in ovarian cancer prognosis and therapeutics

Ovarian cancer (OC) is the third most common gynecological malignancy with the highest mortality worldwide. OC is usually diagnosed at an advanced stage, and the standard treatment is surgery combined with platinum or paclitaxel chemotherapy. However, chemoresistance inevitably appears coupled with the easy recurrence and poor prognosis. Thus, early diagnosis, predicting prognosis, and reducing chemoresistance are of great significance for controlling the progression and improving treatment effects of OC. Recently, much insight has been gained into the non-coding RNA (ncRNA) that is employed for RNAs but does not encode a protein, and many types of ncRNAs have been characterized including long-chain non-coding RNAs, microRNAs, and circular RNAs. Accumulating evidence indicates these ncRNAs play very active roles in OC progression and metastasis. In this review, we briefly discuss the ncRNAs as biomarkers for OC prognosis. We focus on the recent advances of ncRNAs as therapeutic targets in preventing OC metastasis, chemoresistance, immune escape, and metabolism. The novel strategies for ncRNAs-targeted therapy are also exploited for improving the survival of OC patients.

Bioinformatics analysis of the role of aldolase A in tumor prognosis and immunity

Aldolase A (ALDOA) is an enzyme that plays an important role in glycolysis and gluconeogenesis, which is closely related to tumor metabolism. In this study, the overall roles of ALDOA in pan-cancer have been investigated from several aspects using databases and online analysis tools. Using the ONCOMINE database, the expression of ALDOA in various cancers was analyzed. The prognostic role of ALDOA was explored by PrognoScan, GEPIA, and Kaplan–Meier Plotter. The immune-related role of ALDOA and its downstream substrates was decided by TIMER, cBioPortal and String. Our data indicate that ALDOA expression level in lung adenocarcinoma, liver hepatocellular carcinoma, head and neck squamous cell carcinoma is higher than that in normal tissues. Increased expression of ALDOA often indicates a poor prognosis for patients. The correlation between ALDOA and immune infiltration among different tumors is very different. We also investigate the relationship between ALDOA and its upstream/downstream proteins. Our results showed that ALDOA could be used as a biomarker for the tumor prognosis, and could be correlated with the infiltrating levels of macrophages, CD4+ T cells and CD8+ T cells.

MSLN Correlates With Immune Infiltration and Chemoresistance as a Prognostic Biomarker in Ovarian Cancer

Mesothelin (MSLN) is a glycoprotein with various expression degrees in different tumors including mesothelioma, ovarian cancer, pancreatic cancer, etc. MSLN is considered to play an important role in cell survival, proliferation, and tumor progression. Although the expression of MSLN in tumors makes it a potential therapeutic target, its mechanism of action is still unclear, especially its correlation with immune cells infiltration in the tumor microenvironment has not been investigated. In this study, we detected the overexpression of MSLN in ovarian cancer using database analysis and tissue-array staining. We further evaluated the diagnostic value of MSLN and found it was associated with poor overall survival in ovarian cancer. In addition, the high expression of MSLN was significantly related to the immune-related genes and chemoresistant genes. We confirmed the overexpression of MSLN in the chemoresistant ovarian cancer cell lines. Our research suggests that MSLN participates in a variety of pathways related to the suppression of immune activation and promotion of chemoresistance, leading to a poor prognosis in ovarian cancer.

Claudin-12 deficiency inhibits tumor growth by impairing transendothelial migration of myeloid-derived suppressor cells

Migration of myeloid-derived suppressor cells (MDSCs) out of the circulation, across vascular walls, and into tumor is crucial for their immunosuppressive activity. A deeper understanding of critical junctional molecules and the regulatory mechanisms that mediate the extravasation of MDSCs could identify approaches to overcome cancer immunosuppression. In this study we used mice deficient in tight-junction protein Claudin-12 (Cldn12) compared to wild-type mice and found that loss of host Cldn12 inhibited the growth of transplanted tumors, reduced intratumoral accumulation of MDSCs, increased anti-tumor immune responses, and decreased tumor vescular density. Further studies revealed that Cldn12 expression on the cell surface of both MDSCs and endothelial cells is required for MDSCs transit across tumor vascular endothelial cells (ECs). Importantly, expression of Cldn12 in MDSCs was modulated by granulocyte-macrophage colony-stimulating factor (GM-CSF) in an AKT-dependent manner. Therefore, our results indicate that Cldn12 could serve as a promising target for restoring the anti-tumor response by interfering with MDSCs transendothelial migration.

Corrigendum to "Spin structure relation to phase contrast imaging of isolated magnetic Bloch and Néel skyrmions" [Ultramicroscopy 212 (2020) 112973]

Several errors are present in the text and Fig. 3 of the article Ultramicroscopy 212 (2020) 112973. This includes minor confusions concerning the skyrmion helicities and a wrong orientation of a color wheel that represents the electron phase gradient direction. Further, the presented correction factors for finite probe sizes were based on an erratic simulation which is now corrected. This leads to different error values for the measured skyrmion size. These flaws do not affect the main message of the paper which is the relation of the skyrmion structure with the electron phase at all. They only affect the small section of the proof of principle skyrmion size measurement where aberrations were included.

Polysaccharides From Lentinus Edodes Inhibits Lymphangiogenesis via the Toll-Like Receptor 4/JNK Pathway of Cancer-Associated Fibroblasts

Polysaccharides from Lentinus edodes (L. edodes) have been successfully used as adjuvant chemotherapy drug to treat lymphatic metastasis in some malignancies, such as colorectal cancer (CRC), lung cancer and gastric cancer. The CRC could metastasize via lymphatic vessels. Lymphatic metastasis is commonly thought to be the cause of poor prognosis of CRC. The mechanism of polysaccharides from L. edodes inhibiting lymphatic metastasis of CRC is still unclear. In this study, we explored how MPSSS, a novel polysaccharide component of L. edodes, influences lymphangiogenesis and lymph node metastasis. The results show that MPSSS can reduce lymphangiogenesis and lymphatic metastasis of CRC in mouse model. And combined with in vitro study, a likely mechanism is that MPSSS reduce the secretion of VEGF-C by cancer associated fibroblasts (CAFs). This effect can be suppressed by a TLR4 inhibitor, which suggests that MPSSS plays a role in CAFs through the TLR4/JNK signaling pathway. In conclusion, MPSSS may reduce lymphangiogenesis by decreasing the VEGF-C secretion of CAFs, which may provide a new strategy for the comprehensive treatment of CRC.

Low SCRIB expression in fibroblasts promotes invasion of lung cancer cells

AIMS

Cancer associated fibroblasts (CAFs) play a crucial role in lung tumor development, but the underlying mechanism is still not fully understood.

MAIN METHODS

SCRIB expression in the CAFs of human lung cancer tissues was examined by immunohistochemistry (IHC). A coculture of mouse Lewis lung cancer cells (LLC) and fibroblasts was used to investigate SCRIB expression in cocultured fibroblasts. Proliferation, scratch wound, and transwell assays were used to examine the proliferation, migration and invasion ability of SCRIB knockdown fibroblasts and their effects on LLC. A 3D-coculture system and co-injection xenograft model were used to examine LLC invasion. RNA sequencing and transwell experiments were used to explore the molecules that may participate in LLC invasion.

KEY FINDINGS

Herein, we found that the low expression of SCRIB in CAFs is correlated with advanced tumor stages and poor survival for human lung squamous cell carcinoma. SCRIB expression in fibroblasts is drastically downregulated by LLC cells. SCRIB knockdown fibroblasts not only enhance invasion but also facilitate LLC invasion in a 3D-coculture system and in an in vivo subcutaneous transplantation model. The upregulation of asporin in SCRIB knockdown fibroblasts is involved in LLC invasion in vitro.

SIGNIFICANCE

Collectively, the results indicate that fibroblasts with low SCRIB expression promote lung cancer cell invasion, which suggests that the downregulated expression of SCRIB may represent one of the important characteristics of tumor-promoting CAFs in lung squamous cell cancer.

Spin structure relation to phase contrast imaging of isolated magnetic Bloch and Néel skyrmions

Magnetic skyrmions are promising candidates for future storage devices with a large data density. A great variety of materials have been found that host skyrmions up to the room-temperature regime. Lorentz microscopy, usually performed in a transmission electron microscope (TEM), is one of the most important tools for characterizing skyrmion samples in real space. Using numerical calculations, this work relates the phase contrast in a TEM to the actual magnetization profile of an isolated Néel or Bloch skyrmion, the two most common skyrmion types. Within the framework of the used skyrmion model, the results are independent of skyrmion size and wall width and scale with sample thickness for purely magnetic specimens. Simple rules are provided to extract the actual skyrmion configuration of pure Bloch or Néel skyrmions without the need of simulations. Furthermore, first differential phase contrast (DPC) measurements on Néel skyrmions that meet experimental expectations are presented and showcase the described principles. The work is relevant for material sciences where it enables the engineering of skyrmion profiles via convenient characterization.

Long non-coding RNA DANCR promotes cervical cancer growth via activation of the Wnt/β-catenin signaling pathway

Background

Long non-coding RNAs (lncRNAs) are implicated in many pathophysiological processes, including cancers. In particular, lncRNA DANCR is regarded as a cancer-associated lncRNA exerting various regulatory mechanisms. However, the expressions, functions, and mechanisms of action of DANCR in cervical cancer are still unclear.

Methods

The expressions of DANCR in cervical cancer tissues and cell lines were evaluated using qRT-PCR. Correlations between DANCR expression and clinicopathological features and prognosis were analyzed. The roles of DANCR in cervical cancer growth were evaluated by in vitro CCK-8 and EdU assay, and in vivo xenograft assay. The regulatory effects of DANCR on Wnt/β-catenin signaling pathway were evaluated using nuclear proteins extraction, western blot, and qRT-PCR.

Results

DANCR is increased in cervical cancer tissues and cell lines. Increased expression of DANCR is associated with large tumor size, advanced FIGO stage, and poor overall survival of cervical cancer patients. Functional experiments showed that enhanced expression of DANCR promotes cervical cancer cell proliferation in vitro and xenograft growth in vivo. Conversely, DANCR knockdown inhibits cervical cancer cell proliferation in vitro and xenograft growth in vivo. Mechanistic investigation demonstrated that DANCR upregulates the expressions of FRAT1 and FRAT2 and activates the Wnt/β-catenin signaling pathway. Blocking the Wnt/β-catenin signaling pathway abolishes the pro-proliferative roles of DANCR overexpression and anti-proliferative roles of DANCR knockdown.

Conclusions

Our findings suggest DANCR as an oncogenic lncRNA in cervical cancer through activating the Wnt/β-catenin signaling pathway, and imply that DANCR may be a promising prognostic biomarker and therapeutic target for cervical cancer.

[Cancer epidemics and the cancer prevention and control strategies in the United States: a review study]

In the past two decades,the United States made an impressed progress in the prevention and control of cancer that the overall morbidity and mortality of cancer had shown a downward trend, while China had seen an opposite trend. Cancer, one of the major public health concerns in China, has imposed an enormous burden onthe society and individuals. Therefore,in order to scientifically formulate cancer prevention and control policies, it is essential to make a comprehensive understanding of the practical experience in the field of cancer prevention and control from the United States. This article reviews the relevant literature on cancer trends as well as the prevention and control strategies in the United States,depictsthe cancer epidemic situation in the United States in the past 30 years, and summarizes the influencing factors, strategies and intervention experiences that lead to the improvement of cancer epidemic. It highlights the policy support, surveillance and intervention adopted by the United States for the cancer prevention and control. This article is expected to provide some implications and reference for the cancer prevention and control in China.

Evaluation and characterization of anti-RalA autoantibody as a potential serum biomarker in human prostate cancer

Autoantibodies against intracellular tumor-associated antigens (TAAs) are commonly found in human cancers. In this study, we characterized the serum autoantibody response to the RalA, Ras-like GTPase, in patients with prostate cancer (PCa). The autoantibodies were detected by immunofluorescence assay in PCa cell lines, ELISA, and immunoblotting in 339 serum samples from patients with PCa and benign prostatic hyperplasia (BPH), and in normal human sera (NHS). The expression of RalA in prostate tumor tissues was evaluated by immunohistochemistry (IHC) in tumor microarrays. The autoantibody level to RalA (median) in NHS was significantly lower than in PCa (0.053 vs 0.138; P < 0.001) and BPH (0.053 vs 0.132; P < 0.005) groups. The circulating anti-RalA autoantibody could distinguish PCa patients from normal individuals with the area under the receiver operating characteristic (ROC) curve (AUC) performing at 0.861, with sensitivity of 52.9% and specificity of 91.0%. Elevation in serum immunoreactivity was observed in PCa patients after radical prostatectomy. The combined use of both anti-RalA autoantibody and PSA showed a significantly higher discriminatory ability compared with either of those markers alone. RalA protein expression was detected by IHC in 85.3% of tumor tissues from PCa patients, but without significant difference compared to BPH or normal control tissues. Together, our study shows the additional benefits of anti-RalA autoantibody as a potential serological biomarker for PCa, particularly in patients with normal PSA, and further demonstrate the utility of biomarker combinations in the immunodiagnosis of PCa.

Depinning of domain walls in permalloy nanowires with asymmetric notches

Effective control of the domain wall (DW) motion along the magnetic nanowires is of great importance for fundamental research and potential application in spintronic devices. In this work, a series of permalloy nanowires with an asymmetric notch in the middle were fabricated with only varying the width (d) of the right arm from 200 nm to 1000 nm. The detailed pinning and depinning processes of DWs in these nanowires have been studied by using focused magneto-optic Kerr effect (FMOKE) magnetometer, magnetic force microscopy (MFM) and micromagnetic simulation. The experimental results unambiguously exhibit the presence of a DW pinned at the notch in a typical sample with d equal to 500 nm. At a certain range of 200 nm < d < 500 nm, both the experimental and simulated results show that the DW can maintain or change its chirality randomly during passing through the notch, resulting in two DW depinning fields. Those two depinning fields have opposite d dependences, which may be originated from different potential well/barrier generated by the asymmetric notch with varying d.

Abstract 4974: Using serological proteomics analysis to identify anti-nucleophosmin 1 autoantibody in sera from prostate cancer patients as potential diagnositic and prognostic biomarker

Prostate specific antigen (PSA) level test in blood has been widely implemented for the early detection and prediction of prostate cancer (PCa). However, lack of specificity led to overdiagnosis, following by unnecessary biopsies and overtreatment. Therefore, novel serological biomarkers are urgently needed to complement PSA by enhancing its sensitivity and specificity in the diagnosis of PCa. Autoantibodies against intracellular tumor associated antigens (TAAs) are commonly found in various types of human cancers. Their utility in providing insights into tumor biology and as potential cancer biomarkers is well documented. Previous studies have demonstrated that sera from patients with PCa contain autoantibodies that react with TAAs. In this study, we identified and characterized nucleophosmin 1 (NPM1) with 33 kDa molecular weight as an autoantigen by using serological proteomics analysis (SERPA) approach. In the further validation study, it was observed that the level of anti-NPM1 in sera from patients with PCa was significantly higher than that from benign prostatic hyperplasia (BPH) and healthy individuals and receiver operating characteristic (ROC) curve analysis showed high diagnostic value for PCa (area under the curve (AUC):0.805). Interestingly, when considering anti-NPM1 combined with PSA level in sera from PCa patients at the early stage as well as BPH, 100% PCa patients could be identified correctly, while 69.2% patients with BPH who has elevated PSA level were found anti-NPM1 negative. The data suggested that anti-NPM1 can elicit humoral immune response in PCa and might be a potential biomarker for the immunodiagnosis of PCa, and it would be a supplementary of PSA examination to distinguish PCa from BPH.

Key words: prostate cancer; nucleophosmin 1 (NPM1); tumor-associated antigens (TAAs); autoantibodies; serological proteomics analysis (SERPA)

Citation Format: jitian li, Liping Dai, Ningjing Lei, Mengtao Xing, Carlos A. Casiano, Jianying Zhang. Using serological proteomics analysis to identify anti-nucleophosmin 1 autoantibody in sera from prostate cancer patients as potential diagnositic and prognostic biomarker. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4974.

Expression of somatostatin receptor subtype 2 in growth hormone-secreting pituitary adenoma and the regulation of miR-185

INTRODUCTION

Long-acting somatostatin analogs (SSAs) are most widely used to treat growth hormone (GH)-secreting pituitary adenoma. However, approximately 30 % of treated patients show resistance to SSAs, which may be associated with the reduction of somatostatin receptor subtype 2 (SSTR2) mRNA and protein expression.

MATERIALS AND METHODS

The present study used immunohistochemistry to detect the expression of SSTR2 and SSTR5 in twenty human GH-secreting adenoma samples treated with SSAs and seven normal pituitary samples.

RESULTS

The staining intensities of SSTR2 and SSTR5 were stronger in most adenoma samples than in normal pituitary. The expression of SSTR2 tended to be lower in the SSA non-responder group than in responders. A search of the Bioinformatics data bank and the miRCURY™ LNA array confirmed miR-185 as the putative mircoRNA (miRNA) regulating the expression of SSTR2. An in vitro study using Dual Luciferase reporter assay demonstrated that miR-185 likely targets the 3'-UTR of SSTR2 mRNA in the rat pituitary adenoma GH3 cell line. MiR-185 also downregulated or upregulated the expression of SSTR2 mRNA and SSTR2 protein, following transfection with miR-185 mimics or inhibitors, respectively.

CONCLUSION

MiR-185 enhanced the cell proliferation and inhibited the apoptosis of GH3 cells.

Abstract 340: Identification of p62/IMP2 novel targets in breast cancer metastasis

As one of the most common types of cancer in women, breast cancer is far from being well controlled, especially when the cancer spreads to other organs in the body. Therefore, it is important to understand the molecular and cellular mechanism of metastatic breast cancer, and to identify new proteins that regulate the metastatic process, as such proteins may be used as targets for possible therapeutic intervention. Our previous study showed that p62/IMP2 (IGF2 mRNA binding protein 2) is overexpressed in breast cancer tissues. In our present study, some variants were generated with stable overexpression of p62/IMP2 in MDA-MB-231 cells and LM2-4 cells, and we found that overexpression of p62/IMP2 can increase breast cancer cell migration and reduce cell adhesion. We also found that the p62/IMP2 can bind to c-myc mRNA and increase the expression of c-myc in the two cell lines. To identify new p62/IMP2 targets related with cell adhesion, we performed a Human Extracelluar Matrix & Adhesion Molecules PCR Array to see which gene expression changes in the p62/IMP2 overexpressed cells, compared to the control cells. Our results showed that 18 adhesion molecules are up-regulated with the overexpression of p62/IMP2 (Fold regulation&gt;2, p&lt;0.05) while 2 are down-regulated. We selected 7 up-regulated genes (such as CTGF, HTBS1 and COL15A1) and a down-regulated gene (ITGB4) as candidates for the further evaluation by real time PCR. All candidates genes were further verified byRNA immunoprecipitation (RIP). The data from RIP suggested that connective tissue growth factor (CTGF) may be a potential target of p62/IMP2. These results provided evidences for a better understanding of breast cancer metastasis and targets for future anti-metastatic drug design.

Note: This abstract was not presented at the meeting.

Citation Format: Yang Li, Bo Peng, Ningjing Lei, Wei Qian, Giulio Francia, Jianying Zhang. Identification of p62/IMP2 novel targets in breast cancer metastasis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 340. doi:10.1158/1538-7445.AM2015-340

CIP2A regulates cancer metabolism and CREB phosphorylation in non-small cell lung cancer

The cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently characterized endogenous inhibitor of the phosphatase activity of protein phosphatase 2A (PP2A), which extends the half-life of oncogenic protein c-myc and promotes in vivo tumor growth. The function of CIP2A in cancer progression is still poorly understood. To uncover the underlying mechanism of CIP2A-mediated cell proliferation, we implemented a two-dimensional electrophoresis (2DE)-based proteomic approach to examine lung cancer cell H1299 with and without CIP2A. We found 47 proteins differentially expressed where 19 proteins were upregulated and 28 proteins were downregulated. These were categorized into functional groups such as metabolism (25%), transcriptional and translational control (23%), and the signaling pathway and protein degradation (20%). On one hand, we validate our proteomic work by measuring the metabolic change. The knockdown of CIP2A decreased the expression of LDH-A as well as the enzymatic activity, accompanying with a decreased lactate production, an increased NADH/NAD+ ratio and ROS production. On the other hand, we found that CIP2A may regulate CREB activity through bioinformatics analysis. Our following experiments showed that, CIP2A positively regulated the phosphorylation of CREB in response to the serum treatment. Therefore, our proteomic study suggested that CIP2A mediates cancer progression through the metabolic pathway and intracellular signaling cascade.

Abstract 3350: CIP2A regulates cell proliferation via akt signaling pathway in human lung cancer

CIP2A is an intracellular endogenous protein phosphatase 2A (PP2A) inhibitor with oncogenic activities. CIP2A was initially identified as a tumor-associated antigen (TAA) in gastric and liver cancer patients, and it was overexpressed in a variety of cancer types. Recently, we found that CIP2A was overexpressed in human lung cancer specimens as compared to normal lung tissues. The elevated expression of CIP2A in lung cancer cells results in an increased cell proliferation. The observation on the association between CIP2A and AKT phosphorylation at S473 in our lab and other labs suggested the role of CIP2A in regulating AKT phosphorylation. Our preliminary data indicated that CIP2A might promote cell proliferation through AKT signaling pathway under growth factor stimulation. Interestingly, the depletion of CIP2A in lung cancer cells did not induce a global change of AKT phosphatase activity, which implied that CIP2A might recognize specific AKT targets and play certain roles in the signaling pathway. In this study, we identified several AKT substrates specifically targeted by CIP2A, such as Hsp70 and mTOR, by proteomic-based systematic screening. The candidates obtained from our study will expand the understanding on protein-substrate interaction and therefore direct the cancer drug design. Therefore, our study addressed a novel role of CIP2A in mediating cancer progression through interacting with AKT pathway in a substrate-dependent manner.

Citation Format: Ningjing Lei, Bo Peng, Jiangying Zhang. CIP2A regulates cell proliferation via akt signaling pathway in human lung 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 3350. doi:10.1158/1538-7445.AM2014-3350

p90/CIP2A mediates breast cancer cell proliferation and apoptosis

Cancerous inhibitor of PP2A (p90/CIP2A) was recently characterized as an innovative oncoprotein in human malignancies. p90/CIP2A inhibited c-Myc-associated PP2A phosphatase activity to promote cell proliferation and tumor growth. A growing number of studies have demonstrated that the overexpression of p90/CIP2A in various human malignancies. But the function of p90/CIP2A in cancer progression is still poorly understood. In the current research, we aim to explore the biological function of p90/CIP2A in breast cancer. shRNA knockdown was performed in MDA-MB-231 and LM2-4 cell lines. Cell proliferation assay, colony formation assay and flow cytometry were carried out to evaluate the role of p90/CIP2A in cell proliferation and apoptosis. p90/CIP2A depletion in breast cancer cells inhibited proliferation and increased paclitaxel-induced apoptosis. Furthermore, p90/CIP2A silencing down-regulated the expression of c-Myc and the level of p-ERK1/2. Taken together, our data suggest that p90/CIP2A as a crucial oncoprotein has been involved in cell proliferation and apoptosis, which may serve as a therapeutic target in breast cancer treatment.

CIP2A regulates cell proliferation via the AKT signaling pathway in human lung cancer

Cancerous inhibitor of PP2A (CIP2A) is an intracellular endogenous protein phosphatase 2A (PP2A) inhibitor with oncogenic activities. Initially identified as a tumor-associated antigen (TAA) in gastric and liver cancer patients, CIP2A was overexpressed in a variety of cancer types. The overexpression of CIP2A in cancer cells is associated with increased cell proliferation. However, the mechanism of CIP2A in cancer cell proliferation remains poorly understood. In the present study, we reported that CIP2A can regulate AKT phosphorylation at S473 under growth factor stimulation and our results also showed that CIP2A may promote cell proliferation through the AKT signaling pathway. Notably, depletion of CIP2A did not induce a global change of AKT phosphatase activity, which indicated that CIP2A may recognize specific AKT targets and play certain roles in the signaling pathway. In addition, we detected that CIP2A expression was associated with mTOR phosphorylation. Our further analysis corroborated the relationship between CIP2A and AKT-mTOR signaling pathway. Therefore, our study addressed a novel role of CIP2A in mediating cancer progression through interacting with the AKT-mTOR signaling pathway.

Expression and purification of the functional ectodomain of human anthrax toxin receptor 2 in Escherichia coli Origami B cells with assistance of bacterial Trigger Factor

The ectodomain of anthrax toxin receptor 2 (ANTXR2) is composed of a von Willebrand factor A (VWA) domain that binds to anthrax toxin protective antigen (PA) and a newly defined immunoglobulin-like (Ig) domain, in which the disulfide bonds are required for PA pore formation and for the folding of ANTXR2. While the VWA domain has been well characterized, the structure and function of the whole ectodomain (VWA-Ig) are poorly defined, which is mainly due to the limited production of the soluble recombinant protein of the ectodomain. In the present study, the ANTXR2 ectodomain was fused to the C-terminus of bacterial Trigger Factor (TF), a chaperone that mediates the ribosome-associated, co-translational folding of newly synthesized polypeptides in Escherichia coli. Under the control of a cold shock promoter, the fusion protein was overly expressed as a dominant soluble protein at a low temperature in the oxidative cytoplasm of Origami B cells, where formation of the disulfide bonds is favored. Through a series of chromatography, the ANTXR2 ectodomain was purified into homogeneity. The purified ectodomain is functional in binding to PA and mediating PA pore formation on the liposomal membranes, and the yield is applicable for future biochemical and structural characterization.

A novel marine drug, SZ-685C, induces apoptosis of MMQ pituitary tumor cells by downregulating miR-200c

OBJECTIVE

We found a novel marine drug, SZ-685C, that was isolated from the secondary metabolites of a mangrove endophytic fungus (No. 1403) collected from the South China Sea, which has been reported to inhibit the proliferation of certain tumor cells. However, its anticancer mechanism remains unknown. The aims of this study were to observe the effectiveness of SZ-685C on pituitary adenoma cells and determine the underlying mechanisms of action.

METHODS

A rat prolactinoma cell line, MMQ, was used in this study. A dose escalation of SZ-685C was performed on this cell line, and cell viability was assessed using an MTT assay. Hoechst 33342, Annexin V-FITC/PI, TUNEL staining and flow cytometry were used to evaluate the extent of apoptosis at each concentration of SZ-685C. The effect of SZ-685C on prolactin expression was also evaluated using RT-PCR and immunoblotting. Quantitative RT-PCR was used to detect the expression of miR-200c in SZ-685C-stimulated MMQ cells and pituitary adenoma tissues. This miRNA was then overexpressed in MMQ cells via transfection of a miR-200c mimic to identify the mechanism underling the anti-tumor effect of SZ-685C.

RESULTS

SZ-685C inhibited MMQ cell growth in a dose-dependent manner but showed little toxicity toward rat pituitary cells (RPCs). The IC50s of SZ-685C in MMQ cells and RPCs were 13.2 ± 1.3 mM and 49.1 ± 11.5 mM, respectively, which was statistically significant. Increasing numbers of apoptotic cells were observed in response to escalating concentrations of SZ-685C, and the expression level of prolactin (PRL) was inhibited. Nevertheless, the level of PRL mRNA was unchanged. Additionally, miR-200c was upregulated in MMQ cells compared with RPCs, and downregulation of miR- 200c was observed in SZ-685C-treated MMQ cells. Furthermore, the overexpression of miR-200c weakened the effect of SZ-685C-induced apoptosis of MMQ cells.

CONCLUSIONS

Our results suggest that SZ-685C induces MMQ cell apoptosis in a miR-200c-dependent manner. Therefore, SZ-685C might be a useful alternative treatment for pituitary adenoma.

Peroxiredoxin 1 is a tumor-associated antigen in esophageal squamous cell carcinoma

Peroxiredoxin 1 (Prdx1) is an antioxidant and plays an important role in H2O2-mediated cell signaling. We previously found that the expression level of Prdx1 was elevated in esophagus squamous cell carcinoma (ESCC) tissue using a proteomics approach. Since overexpressed protein can induce an autoimmune response, to further examine whether serum from ESCC patients exhibits immunoreactivity against Prdx1, autoantibody responses to Prdx1 were evaluated by ELISA, western blotting and indirect immunofluorescence assay in sera from patients with ESCC and normal individuals. Immunohistochemical study with tissue array slides and western blot analysis with cancer cell lines were also performed to analyze the protein expression profiles of Prdx1 in ESCC tissues and cancer cell lines. The results demonstrated that the positive rate of autoantibody against Prdx1 in ESCC sera was 13.2% (9/68), whereas this rate was 0% (0/89) in normal individuals. Data also showed that expression of Prdx1 was significantly increased in ESCC tissues when compared to expression in paired adjacent normal tissues (P<0.05). The data indicate that Prdx1 may contribute to malignant transformation of the esophagus, and may be used as a biomarker in the immunodiagnosis of ESCC.

Autoantibodies to tumor-associated antigens as biomarkers in human hepatocellular carcinoma (HCC)

Tumor-associated antigens (TAAs) recognized by cellular and/or humoral effectors of the immune system are attractive targets for diagnostic and therapeutic approaches to human cancer. Different approaches can be used to comprehensively characterize and validate the identified TAA/anti-TAA systems, which are potential biomarkers in cancer immunodiagnosis. Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. The high fatality rate of HCC within one year after its detection might be partly attributed to a lack of diagnostic methods that enable the early detection. Our previous studies have shown that novel autoantibodies can appear which are not detected prior to pre-malignant conditions during transition from chronic liver disease to HCC. The hypothesis we advance is the transition to malignancy can be associated with autoantibody response to certain cellular proteins that might have some role in tumorigenesis. We propose that the information that the cancer patient’s immune system is conveying in the form of autoantibodies to tumor-associated antigens (TAAs) should be utilized to a greater extent in identifying early signs of tumorigenesis. In this review, we will focus on the important features of TAA and the possibility that autoantibodies to TAAs can be used as biomarkers in immunodiagnosis and prognosis of HCC.

Abstract 5381: p62/IMP2 promotes hepatocellular carcinoma (HCC) progression

Autoantibodies to autologous cellular antigens in cancer patients have been considered as reporters identifying antigenic changes in cellular factors involved in the transformation process. We have made use of such autoantibodies from hepatocellular carcinoma patients to immunoscreen a cDNA expression library and have identified a cytoplasmic RNA-binding protein p62. Autoantibodies to p62 have been detected in up to 21% of a cohort of hepatocellular carcinoma (HCC) patients. Further study has demonstrated that p62 is a member of insulin-like growth factor 2 mRNA binding protein family (IMPs), which is an isoform of IMP2. The three members of the IMP family (IMP1, 2 and 3) have been found to regulate translation of insulin-like growth factor 2 (IGF2) mRNA in a post-transcriptional manner. Since several studies have suggested that IMP1 and IMP3 play important roles in cancer progression, whether p62/IMP2 can also play a role in cancer formation remains to be investigated. In this study, we intend to interrogate the role of p62/IMP2 in HCC formation. We found that the expression of p62/IMP2 (57.5%) is significantly higher in HCC specimen than that in normal liver tissue (15.4%) by immunohistochemistry study. Furthermore, p62/IMP2 is detected to be overexpressed in several liver cancer cell lines. Depletion of p62/IMP2 via lentivirus-mediated knockdown in SNU449 liver cancer cell line decreased the cell proliferation. On the contrary, the ectopic overexpression of p62/IMP2 increased cell proliferation. Our data suggested that p62/IMP2 is overexpressed in liver cancer and is functionally correlated with cancer cell growth.

Citation Format: Ningjing Lei, Bo Peng, Yang Li, Yurong Chai, Jianying Zhang. p62/IMP2 promotes hepatocellular carcinoma (HCC) progression. [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 5381. doi:10.1158/1538-7445.AM2013-5381

Autoantibodies against glucose-regulated protein 78 as serological diagnostic biomarkers in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a type of cancer with a very poor prognosis. Although α-fetoprotein (AFP) is the most effective marker available to detect HCC, the sensitivity and specificity are not optimal. Therefore, there is a need for the development of more sensitive and specific methods that can supplement AFP in the early detection of this cancer. In this study, autoantibody responses to glucose-regulated protein 78 (GRP78) were evaluated by enzyme-linked immunosorbent assay (ELISA), western blotting and indirect immunofluorescence assay in sera from patients with HCC, liver cirrhosis (LC) and chronic hepatitis (CH), as well as from normal human individuals. Immunohistochemistry (IHC) with tissue array slides was also preformed to analyze protein expression profiles of GRP78 in HCC and control tissues. The prevalence of autoantibodies against GRP78 was 35.5% (27/76) in HCC, which was significantly higher than that in LC, CH and normal human sera (NHS; P<0.01). The average titer of autoantibodies against GRP78 in HCC sera was higher compared to that in LC, CH and NHS(P<0.01). When both autoantibodies against GRP78 and AFP were used simultaneously as diagnostic markers, sensitivity reached 71.4%. Our data indicate that anti-GRP78 autoantibodies may be potential diagnostic markers for HCC, especially in conjunction with AFP.

Abstract 4801: p90/CIP2A may play a role in regulating the phosphorylation of CREB1 in cancer

Cancerous inhibitor of PP2A (CIP2A) is a tumor-associated autoantigen migrating in SDS-PAGE as a protein of 90kD (also called p90). This protein was shown to be expressed in the mouse embryonic stage but inactivated in adult tissues. It has been shown to inhibit PP2A function thus stabilizing the oncogene c-myc in human malignancies. In the present study, we used two-dimensional electrophoresis-based approach and identified 47 differentially expressed proteins upon the loss of p90/CIP2A in H1299 lung cancer cell line. Among these 47 proteins, 30 proteins have been well documented to be associated with cancer, of which 12 proteins are up-regulated and 18 proteins are down-regulated after knock-down of p90/CIP2A via shRNA. To investigate whether these proteins are associated with any known cancer-related pathway, differentially expressed proteins were analyzed using Pathway Studio bioinformatics software. The resulting data indicated that four possible transcription factors (c-myc, ESR-1, ETS-1 and CREB) may involve in the regulation of the differentially expressed proteins. Further studies showed that down-regulation of p90/CIP2A may affect CREB phosphorylation: treatment with serum induced less phosphorylation of CREB in cells transduced with p90/CIP2A shRNA than the cells tranduced with control shRNA. However, other treatments like KCl and forskolin did not show significant difference between these two groups. We also found that the phosphorylation of the CREB upstream kinase, AKT, was also down-regulated while other kinases p38 and p90RSK was unaffected. These preliminary data imply that p90/CIP2A may target AKT-CREB pathway to promote cell proliferation in a c-myc independent manner.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4801. doi:1538-7445.AM2012-4801

High-resolution extracellular stimulation of dispersed hippocampal culture with high-density CMOS multielectrode array based on non-Faradaic electrodes

We introduce a method to electrically stimulate individual neurons at single-cell resolution in arbitrary spatiotemporal patterns with precise control over stimulation thresholds. By exploiting a custom microelectronic chip, up to 65,000 non-Faradaic electrodes can be uniquely addressed with electrode density exceeding 6500 electrodes mm(-2). We demonstrate extracellular stimulation of dispersed primary hippocampal neuronal cultures using the chip at single-cell resolution.

Morphology of monolayer Cu x Au 1-x on Cu(001)

Protruding nanostructure is produced in the single layer of Cu(x)Au(1 - x) surface alloy grown on Cu(001) due to the mismatch strain which has been utilized as a template to tune the magnetic anisotropy of overlays recently. The protrusion network was investigated by in situ scanning tunneling microscopy (STM) combined with low energy electron diffraction (LEED) as a function of the stoichiometry. The measurement revealed the structure of the protrusion and its correlation with the composition. Interestingly, we observed a twin-domain phase of the protrusion when the film approaches the fully hetero-epitaxial range.

Magnetocrystalline anisotropy in permalloy revisited

Permalloy with a body-centered-cubic structure has been grown on GaAs(001) by molecular beam epitaxy. Its magnetism, Curie temperature, and magnetic anisotropy are determined experimentally and compared to those of conventional face-centered-cubic Permalloy. Unexpectedly the vanishing magnetic cubic anisotropy in Permalloy is found to be independent of its atomic structure but depends only upon the stoichiometry of Fe and Ni in the FexNi1-x alloy. This observation is further investigated and confirmed by first-principles electronic band calculations, which help to understand the long-standing issue of why Permalloy should be a soft magnet.

Existence of a flat phase in red cell membrane skeletons

Biomolecular membranes display rich statistical mechanical behavior. They are classified as liquid in the absence of shear elasticity in the plane of the membrane and tethered (solid) when the neighboring molecules or subunits are connected and the membranes exhibit solid-like elastic behavior in the plane of the membrane. The spectrin skeleton of red blood cells was studied as a model tethered membrane. The static structure factor of the skeletons, measured by small-angle x-ray and light scattering, was fitted with a structure factor predicted with a model calculation. The model describes tethered membrane sheets with free edges in a flat phase, which is a locally rough but globally flat membrane configuration. The fit was good for large scattering vectors. The membrane roughness exponent, zeta, defined through h alpha L zeta, where h is the average amplitude of out-of-plane fluctuations and L is the linear membrane dimension, was determined to be 0.65 +/- 0.10. Computer simulations of model red blood cell skeletons also showed this flat phase. The value for the roughness exponent, which was determined from the scaling properties of membranes of different sizes, was consistent with that from the experiments.