Tissue Microarray Immunohistochemistry Research Articles

Increased placental expression of Placental Protein 5 (PP5) / Tissue Factor Pathway Inhibitor-2 (TFPI-2) in women with preeclampsia and HELLP syndrome: Relevance to impaired trophoblast invasion?

IntroductionPlacental Protein 5 (PP5)/Tissue Factor Pathway Inhibitor-2 (TFPI-2) is an extracellular matrix-associated protein mainly expressed by the syncytiotrophoblast that may regulate trophoblast invasion. Our aim was to study placental PP5/TFPI-2 expression and its relation to placental pathology in various forms of preeclampsia and HELLP syndrome. MethodsPlacental and maternal blood specimens were collected at the time of delivery from the same women in the following groups: 1) early controls; 2) early preeclampsia; 3) early preeclampsia with HELLP syndrome; 4) late controls; and 5) late preeclampsia. After histopathological examination, placental specimens were immunostained with polyclonal anti-PP5/TFPI-2 antibody on Western blot and tissue microarray immunohistochemistry. Placental PP5/TFPI-2 immunoscores were assessed manually and with a semi-automated method. Maternal sera were immunoassayed for PP5/TFPI-2. ResultsPP5/TFPI-2 was localized to the cytoplasm of syncytiotrophoblast. Manual and semi-automated PP5/TFPI-2 immunoscores were higher in early preeclampsia with or without HELLP syndrome but not in late preeclampsia than in respective controls. In patients with preeclampsia, the correlation of placental PP5/TFPI-2 expression with maternal vascular malperfusion score of the placenta was positive while it was negative with birthweight and placental weight. Maternal serum PP5/TFPI-2 concentration was higher in early preeclampsia and it tended to be higher in early preeclampsia with HELLP syndrome than in early controls. DiscussionOur findings suggest that an increased placental PP5/TFPI-2 expression may be associated with abnormal placentation in early preeclampsia, with or without HELLP syndrome.

MYH9 Promotes Growth and Metastasis via Activation of MAPK/AKT Signaling in Colorectal Cancer.

The contractile protein MYH9 (non-muscle myosin IIA) is an actin-binding protein that plays a fundamental role in cell adhesion, migration, and division. However, its distinct role in colorectal cancer (CRC) still remains unidentified. In this study, we detected significant MYH9 overexpression in CRC samples compared with paired normal tissues using western blotting and tissue microarray immunohistochemistry (IHC). Moreover, analysis of patient clinical information demonstrated that MYH9 overexpression was strongly correlated with lymph node metastasis and poor overall survival. Endogenous overexpression of MYH9 enhanced the ability of cell proliferation and migration in vitro, and accelerated CRC growth in mouse models. Silencing of MYH9 revealed repressive effects on CRC cells in vitro and in vivo. Furthermore, primary biomechanics that involved MAPK/AKT signaling mediated epithelial-mesenchymal transition (EMT) was uncovered underlying MYH9 dependent cell behaviors. Collectively, our data showed that MYH9 significantly promoted tumorigenesis by regulating MAPK/AKT signaling, and was remarkably correlated with poor prognosis in CRC. MYH9 may thus be a novel biomarker and drug target in the diagnosis and treatment of CRC.

GRK5 promotes tumor progression in renal cell carcinoma.

GRK5 is a multifunctional protein that is able to move within the cell in response to various stimuli to regulate key intracellular signaling from receptor activation, on plasmamembrane, to gene transcription, in the nucleus. Thus, GRK5 is involved in the development and progression of several pathological conditions including cancer. Here, we report an important tumor-promoting role for GRK5 in renal cell carcinoma (RCC). We investigated the expression pattern, clinical significance, and function of GRK5 in RCC. By using quantitative real-time polymerase chain reaction (qRT-PCR) and tissue microarray (TMA) immunohistochemistry (IHC), we first demonstrated that compared with paired adjacent nontumor (NT) tissues, RCC tissues presented with higher GRK5 expression. Moreover, we found that GRK5 upregulation was associated with poor clinical outcomes in RCC patients. In vitro, we found that GRK5 knockdown reduced viability, invasive ability, migratory ability, and decreased proportion of cells in S phase, with concomitant increase in G1 phase in RCC cell lines, while GRK5 overexpression promoted tumor cell proliferation, cell invasion, migration and increased proportion of cells in S phase, with concomitant decrease in G1 phase. Collectively, our findings describe the tumour-promoting role of GRK5 in RCC and thus provide molecular evidence for new therapeutic options in RCC.

CBP/β-Catenin/FOXM1 Is a Novel Therapeutic Target in Triple Negative Breast Cancer

Background: Triple negative breast cancers (TNBCs) are an aggressive BC subtype, characterized by high rates of drug resistance and a high proportion of cancer stem cells (CSC). CSCs are thought to be responsible for tumor initiation and drug resistance. cAMP-response element-binding (CREB) binding protein (CREBBP or CBP) has been implicated in CSC biology and may provide a novel therapeutic target in TNBC. Methods: RNA Seq pre- and post treatment with the CBP-binding small molecule ICG-001 was used to characterize CBP-driven gene expression in TNBC cells. In vitro and in vivo TNBC models were used to determine the therapeutic effect of CBP inhibition via ICG-001. Tissue microarrays (TMAs) were used to investigate the potential of CBP and associated proteins as biomarkers in TNBC. Results: The CBP/ß-catenin/FOXM1 transcriptional complex drives gene expression in TNBC and is associated with increased CSC numbers, drug resistance and poor survival outcome. Targeting of CBP/β-catenin/FOXM1 with ICG-001 eliminated CSCs and sensitized TNBC tumors to chemotherapy. Immunohistochemistry of TMAs demonstrated a significant correlation between FOXM1 expression and TNBC subtype. Conclusion: CBP/β-catenin/FOXM1 transcriptional activity plays an important role in TNBC drug resistance and CSC phenotype. CBP/β-catenin/FOXM1 provides a molecular target for precision therapy in triple negative breast cancer and could form a rationale for potential clinical trials.

Inactivation of RUNX3 protein expression in tongue squamous cell carcinoma and its association with clinicopathological characteristics.

The function of runt-related transcription factor 3 (RUNX3) in oral cancer remains controversial. The present study aimed to determine the status of RUNX3 protein expression and its association with clinicopathological characteristics in tongue squamous cell carcinomas (SCC). The present study used three pairs of tongue SCC and non-cancerous tissues to assess RUNX3 protein expression by western blot analysis, and two tongue SCC cell lines to determine RUNX3 protein localization by immunofluorescence and immunocytochemistry. Tissue microarray immunohistochemistry was performed to detect the clinical relevance of RUNX3 in 79 patients with tongue SCC. The results demonstrated that RUNX3 protein expression was reduced in tongue SCC tissues compared with in paired non-cancerous tissues. Similarly, the expression of RUNX3 was low in SCC25 and Cal27 cells, and was predominantly localized to the cytoplasm. In the 79 patients with tongue SCC, RUNX3 protein expression was presented in different manners in carcinoma nests and tumor stroma. RUNX3 in carcinoma nests (nRUNX3) exhibited nuclear positive staining in 24/79 samples, cytoplasmic mislocalization in 41/79 samples and was undetectable in 14/79 samples. RUNX3 in stroma (sRUNX3) exhibited nuclear positive staining in 40/79 samples and nuclear negative staining in 39/79 samples. Negative nRUNX3 expression was significantly associated with lymph node metastasis (P=0.014), clinical stage (P=0.027), and overall and disease-free survival (P=0.008 and P=0.007, respectively). In addition, negative sRUNX3 expression was associated with lymph node metastasis (P=0.003) and clinical stage (P=0.003); however, not with overall survival. The findings of the present study preliminarily suggested that cytoplasmic mislocalization of RUNX3 protein may be a common event in tongue SCC, and that sRUNX3 protein expression may be a potential prognostic biomarker.

Integrated eicosanoid lipidomics and gene expression reveal decreased prostaglandin catabolism and increased 5-lipoxygenase expression in aggressive subtypes of endometrial cancer.

Eicosanoids comprise a diverse group of bioactive lipids which orchestrate inflammation, immunity, and tissue homeostasis, and whose dysregulation has been implicated in carcinogenesis. Among the various eicosanoid metabolic pathways, studies of their role in endometrial cancer (EC) have very much been confined to the COX-2 pathway. This study aimed to determine changes in epithelial eicosanoid metabolic gene expression in endometrial carcinogenesis; to integrate these with eicosanoid profiles in matched clinical specimens; and, finally, to investigate the prognostic value of candidate eicosanoid metabolic enzymes. Eicosanoids and related mediators were profiled using liquid chromatography-tandem mass spectrometry in fresh frozen normal, hyperplastic, and cancerous (types I and II) endometrial specimens (n = 192). Sample-matched epithelia were isolated by laser capture microdissection and whole genome expression analysis was performed using microarrays. Integration of eicosanoid and gene expression data showed that the accepted paradigm of increased COX-2-mediated prostaglandin production does not apply in EC carcinogenesis. Instead, there was evidence for decreased PGE2 /PGF2α inactivation via 15-hydroxyprostaglandin dehydrogenase (HPGD) in type II ECs. Increased expression of 5-lipoxygenase (ALOX5) mRNA was also identified in type II ECs, together with proportional increases in its product, 5-hydroxyeicosatetraenoic acid (5-HETE). Decreased HPGD and elevated ALOX5 mRNA expression were associated with adverse outcome, which was confirmed by immunohistochemical tissue microarray analysis of an independent series of EC specimens (n = 419). While neither COX-1 nor COX-2 protein expression had prognostic value, low HPGD combined with high ALOX5 expression was associated with the worst overall and progression-free survival. These findings highlight HPGD and ALOX5 as potential therapeutic targets in aggressive EC subtypes. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

539P - Pre-diagnostic anthropometry, sex, and risk of colorectal cancer according to tumor-infiltrating immune cell composition

Background: Obesity is a well-established risk factor for colorectal cancer (CRC), but whether this risk differs according to CRC subtype defined by the tumor immune microenvironment has been sparsely described. Herein, we examined the relationship between pre-diagnostic anthropometry and CRC risk according to tumor-infiltrating immune cell composition, with particular reference to potential sex differences. Methods: The density of immune cells expressing PD1, PD-L1 (PD-L1/IC), CD3, CD8, FoxP3, CD20, CD68, CD163, and tumor cells expressing PD-L1 (PD-L1/TC) was assessed by immunohistochemistry in tissue microarrays with tumors from 584 incident CRC cases in the Malmo Diet and Cancer Study (n = 28098). Multivariable Cox regression models, adjusted for age, smoking and alcohol intake, were applied to calculate hazard ratios (HR) for CRC risk according to height, weight, bodyfat %, waist- and hip circumference, waist-hip ratio (WHR), body mass index (BMI), and different immune cell subsets. Results: Obesity, measured as several anthropometric factors, was significantly associated with PD-L1+/TC low, CD8+ high, FoxP3+ low, CD20+ low, and CD163+ low tumors in both sexes, and with PD1+ low tumors in women. A contrasting risk between sexes was seen for PD-L1/IC+ tumors, in that obesity was significantly associated with risk of PD-L1/IC+ high tumors in women (ptrend for weight = 0.008, ptrend for BMI = 0.039), but with risk of PD-L1/IC+ low tumors in men (ptrend for weight = 0.005, ptrend for bodyfat % = 0.003, ptrend for waist <0.001, ptrend for hip = 0.012, ptrend for BMI = 0.001, ptrend for WHR <0.001). Furthermore, obesity was associated with risk of any CD3+ high or low and any CD68+ high or low tumors in both sexes, and with any PD1+ high or low tumors in men. In age and BMI-adjusted survival analysis, PD1+, CD8+, CD20+, and CD68+ high were favorable prognostic factors only in women, and FoxP3+ high only in men. High PD-L1+ and CD3+ expression was prognostic in both sexes. Conclusions: Anthropometric factors may influence the immune landscape of colorectal cancer, possibly in a sex-dependent manner. Thus, obesity and sex may be important factors to take into account when stratifying patients for immunotherapy. (Less)

Profilin-1 deficiency leads to SMAD3 upregulation and impaired 3D outgrowth of breast cancer cells

BackgroundAdhesion-mediated activation of FAK/ERK signalling pathway, enabled by the formation of filopodial protrusions (FLP), has been shown to be an important event for triggering of dormancy-to-proliferation switch and metastatic outgrowth of breast cancer cells (BCC). We studied the role of actin-binding protein profilin1 (Pfn1) in these processes.MethodsQuantitative immunohistochemistry (IHC) of BC tissue microarray (TMA) and survival analyses of curated transcriptome datasets of BC patients were performed to examine Pfn1’s association with certain clinicopathological features. FLP formation and single cell outgrowth of BCC were assessed using a 3D matrigel culture that accurately predicts dormant vs metastatic outgrowth phenotypes of BCC in certain microenvironment. Gene expression studies were performed to identify potential biological pathways that are perturbed under Pfn1-depleted condition.ResultsLower Pfn1 expression is correlated with lower nuclear grade of breast tumours and longer relapse-free survival of BC patients. Pfn1 depletion leads to defects in FLP and outgrowth of BCC but without impairing either FAK or ERK activation. Guided by transcriptome analyses, we further showed that Pfn1 depletion is associated with prominent SMAD3 upregulation. Although knockdown and overexpression experiments revealed that SMAD3 has an inhibitory effect on the outgrowth of breast cancer cells, SMAD3 knockdown alone was not sufficient to enhance the outgrowth potential of Pfn1-depleted BCC suggesting that other proliferation-regulatory pathways in conjunction with SMAD3 upregulation may underlie the outgrowth-deficient phenotype of BCC cells upon depletion of Pfn1.ConclusionOverall, these data suggest that Pfn1 may be a novel biomarker for BC recurrence and a possible target to reduce metastatic outgrowth of BCC.

The ambiguous role of microRNA-205 and its clinical potential in pancreatic ductal adenocarcinoma

Early treatment of pancreatic ductal adenocarcinoma (PDAC) is significantly delayed due to the lack of liquid biopsy markers for early diagnosis at surgically resectable tumor stages. Recent studies suggest that microRNA-205 (miR-205) is involved in PDAC progression by post-transcriptional regulation of epithelial-to-mesenchymal transition (EMT). However, the clinical potential of miR-205 as diagnostic and prognostic marker remains undefined and its exact role in PDAC is still ambiguous. This retrospective study is a substantial contribution to this on-going scientific discussion. Expression analysis of miR-205 and its molecular targets in PDAC cell lines (n = 5), human tissue (n = 73), and blood serum samples (n = 85) by qRT-PCR, tissue microarray immunohistochemistry, and western blot. Descriptive and explorative statistical analysis of miR-205's clinical potential for diagnosis and prognosis of PDAC. The expression of miR-205 differs more than 2000-fold (p < 0.001) between epithelial and mesenchymal-like human PDAC cell lines correlating with EMT-marker expression of E-cadherin, vimentin, fibronectin, and ZEB-1. Expression of miR-205 is significantly upregulated in carcinoma tissue (eightfold, p = 0.028) and serum (2.3-fold, p = 0.023) of PDAC patients compared to age-matched healthy controls. In our patient collective circulating miR-205 in combination with CA.19-9 outperforms the diagnostic accuracy of CA.19-9 alone with an AUC of 0.890 (p < 0.001), sensitivity of 0.867, and specificity of 0.933. Though non-significant, low expression of circulating miR-205 is more frequent in advanced tumor stages combined with a worse overall survival (6.9 vs. 11.9 months, p = 0.176). Besides its controversial role in carcinogenesis, miR-205 shows high potential as a solid and liquid biopsy marker in PDAC. This result is an urgent call for larger confirmatory multi-center studies.

Imbalanced expression pattern of steroid receptor coactivator-1 and -3 in liver cancer compared with normal liver: An immunohistochemical study with tissue microarray.

Steroids affect normal and pathological functions of the liver through receptors, which require coactivators for their transcriptional activation. Steroid receptor coactivator (SRC)-1 and SRC-3 have been demonstrated to be regulated in numerous cancers; however, their expression profiles in liver cancer including hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC) remain unclear. Using tissue microarray immunohistochemistry, normal liver tissue and HCC tissue exhibited immunoreactivity of SRC-1, which were predominantly localized within extranuclear components; in CCC, they were detected within the cell nuclei; SRC-3 was also detected in the cell nuclei. Furthermore, no altered expression of SRC-1 and SRC-3 was observed in liver cancer compared with normal liver tissue; however, in CCC, the expression of SRC-3 was significantly increased compared with that detected in HCC. Importantly, although expression of SRC-1 and SRC-3 did not reveal any significant differences (30 vs. 40%) in normal liver tissue, HCC and CCC expression of SRC-1 was significantly decreased compared with that of SRC-3 (9.3 vs. 36%, and 6.7 vs. 67.7% for HCC and CCC, respectively). Further comparative analysis revealed that this discrepancy was detected in males with liver cancer, across all ages of HCC cases, younger CCC cases and all stages of liver cancer. The results suggested the presence of an imbalanced expression pattern of SRC-1 and SRC-3 from normal liver tissue to liver cancer (decreased SRC-1 and increased SRC-3), which may affect hepatic function and therefore promote liver carcinogenesis.

Overexpression of ADAMTS-2 in tumor cells and stroma is predictive of poor clinical prognosis in gastric cancer

ADAMTS-2 is a member of the ADAMTS family and is a procollagen N-proteinase. The objective of our research is to explore the prognostic significance of ADAMTS-2 in gastric carcinoma. A total of 655 samples with full clinicopathological data were investigated in this study. Tissue microarray immunohistochemistry analysis was used to analyze the relationship between clinicopathological characteristics and ADAMTS-2 expression. Oncomine and Kaplan-Meier plotters were performed for the relationship analysis between prognosis and ADAMTS-2 expression in patients with gastric cancer. Compared with that of normal tissues, the ADAMTS-2 protein expression was remarkably higher in gastric cancer cells and fibroblast cells. The results of univariate analysis indicated that the expression of ADAMTS-2 in tumor cells and fibroblast cells, Laurén classification, TNM grade, and carcinoembryonic antigen level in gastric cancer were all correlated with overall survival. The results of multivariate analysis indicated that the high expression of ADAMTS-2 in gastric cancer cells and fibroblast cells both were independent prognostic factors. Therefore, ADAMTS-2 may be a potential biomarker for assessing the prognosis of gastric carcinoma.

Increased Expression of CD81 in Breast Cancer Tissue is Associated with Reduced Patient Prognosis and Increased Cell Migration and Proliferation in MDA-MB-231 and MDA-MB-435S Human Breast Cancer Cell Lines In Vitro.

BackgroundCD81, a member of the tetraspanin family, is overexpressed in several tumor types, but its role in breast cancer remains unknown. The present study aimed to investigate the effects of increased CD81 expression on cell migration and proliferation in breast cancer cell lines, MDA-MB-231 and MDA-MB-435S in vitro, and the effects of increased CD81 expression in breast cancer tissue microarrays on patient prognosis.Material/MethodsThe expression of CD81 was evaluated using immunohistochemistry in a human breast cancer tissue microarray containing 140 tumor tissues and a microarray containing 77 normal breast tissues. The effects of increased CD81 expression on cell proliferation and migration in breast cancer cell lines, MDA-MB-231 and MDA-MB-435S, were evaluated by proliferation, transwell migration, and cell counting kit-8 (CCK-8) assays. CD81-expressing plasmid transfection upregulated CD81 expression, and short hairpin RNA (shRNA) lentivirus silenced CD81 expression in vitro.ResultsCD81 expression was significantly increased in breast cancer tissues compared with normal breast tissues (P<0.05). Increased expression of CD81 was significantly associated with lymph node metastasis (P<0.05), clinical stage (P<0.05) and with reduced overall survival (OS) in patients with breast cancer (P<0.05). Increased CD81 expression in MDA-MB-231 and MDA-MB-435S cells promoted cell proliferation and migration, which were inhibited by CD81 silencing.ConclusionsThe findings of the study showed that CD81 might be a potential prognostic biomarker associated with poor patient prognosis in breast cancer. These findings should be investigated further with large-scale controlled prospective studies in patients with breast cancer.

Bcl-2-associated athanogene 3(BAG3) is associated with tumor cell proliferation, migration, invasion and chemoresistance in colorectal cancer

BackgroundCRC is one of the most common malignancies worldwide, and its molecular mechanisms remain unclear. Elevated levels of BAG3 have been reported in various tumors. The present study aimed to explore the expression and function of BAG3 in CRC.MethodsBAG3 protein expression was evaluated in 90 CRC specimens using immunohistochemistry in tissue microarrays, and the correlation between BAG3 expression and the clinicopathological features were assessed. In HCT116 cells BAG3 overexpression cell models were constructed, and CRISPR/Cas9 was used for BAG3 knockout. Western blotting and quantitative real-time PCR were used to determine BAG3 expression in HCT-116 Cells. Cell proliferation, migration and invasion were analyzed by cell counting, colony formation assay, EdU cell proliferation assay, RTCA growth curve assays, wound-healing migration assay and transwell invasion assay. The influence of BAG3 expression level on chemoresistance in HCT-116 cells was examined. Gene expression microarray and IPA analyses were employed to explore signaling pathways associated with the control of BAG3.ResultsUsing immunohistochemistry, this study found that BAG3 was markedly upregulated in colorectal cancer tissues and that BAG3 levels were significantly associated with tumor size and gender. BAG3 overexpression promoted HCT-116 cell growth, migration and invasion in vitro. In contrast, BAG3 knockout inhibited HCT-116 cell growth, migration and invasion. HCT-116 cells with high expression of BAG3 had higher cell viability and lower apoptosis rate than control cells after treatment with 5-FU, while the BAG3 knockout group demonstrated the opposite effects. So BAG3 expression level was associated with chemoresistance to 5-FU in HCT-116 cells. Gene expression microarrays and bioinformatics analyses of HCT-116 cells with BAG3 knockout demonstrated the involvement of BAG3 in signaling pathways associated with the control of cell proliferation, migration, invasion and chemoresistance in CRC.ConclusionsIn conclusion, this study provided evidence that BAG3 has a relevant role in CRC biology, and defined potential molecular pathways and networks. So BAG3 may be considered as a potential therapeutic target for anti-tumor therapy in colorectal cancer.

SLC5A12 is a prognostic marker in head and neck squamous cell carcinoma

Background: Solute carrier family 5 (sodium/monocarboxylate cotransporter) member 12 (SLC5A12) is a low-affinity sodium-coupled lactate transporter. Tumor cells are known to selectively upregulate nutrient transporters such as lactate transporters to support their rapid growth. The goal of this study was to measure SLC5A12 levels in head and neck squamous cell carcinoma (HNSCC) and explores the association of SLC5A12 expression and prognosis in HNSCC. Methods: We determined the expression levels of SCL5A12 mRNA in HNSCC tissues and adjacent normal tissues by quantitative reverse transcription PCR and SLC5A12 protein expression by western blot and tissue microarray immunohistochemistry. SLC5A12 expression was analyzed using UALCAN online resources. Results: SCL5A12 mRNA and protein levels were significantly higher in HNSCC tissues than in adjacent normal tissues. High SCL5A12 protein levels were also associated with lymph node metastasis and higher clinical staging. Conclusions: We conclude that SCL5A12 is a potential indicator for HNSCC development and progression, and that detection of its expression could be a useful independent marker of HNSCC prognosis in the Chinese population.

PO-296 Elucidating the potential role of CD109 as a biomarker for cancer stem-like cells in cervical cancer

IntroductionCervical cancer is a common genital tract cancer. Radiotherapy is the mainstay of management for advanced cervical cancer. Response to radiation varies widely which may be explained by the existence of cancer stem-like cells (CSCs). Since CSCs is implicated in cervical cancer and demonstrated a high degree of resistance to radiation, the identification of novel CSC markers could be critical to specifically target the cervical CSC. In our pilot study, we established attached and spheroid cells from primary cervical tumour tissue. Multiple ‘stemness’ genes were detected in spheroid cells which indicated primary cervical cancer tissue harboured CSCs population. cDNA microarray analysis was performed to compare cDNA expression profile and CD109 was significantly up-regulated in spheroid cells. Therefore, we hypothesise that CD109 may serve as a potential cervical CSCs marker.Material and methodsFlow cytometry was performed to analyse the CD109 expression and isolate the CD109 positive and negative sub-populations in cervical cancer cells. Following the sorting, cell proliferation and migration assay were performed. In order to investigate the effect on the blockade of CD109, SiHa, Caski and C4-1 cells were transfected with CD109 siRNAs. XTT assay, migration and invasion assay and spheroid formation assay were performed. Immunohistochemistry (IHC) was performed for the detection of CD109 expression in cervical cancer tissue microarray (TMA).Results and discussionsThe post-sorted CD109 (+) cells grew remarkably faster and have stronger migration capability than CD109(-) cells in Caski and C4-1. The CD109 knockdown cells with siRNA exhibited a slower cell growth, decreasing migration and self-renewal ability, as compared with the control group in SiHa, Caski and C4-1 cells. IHC of TMA indicated that CD109 was highly expressed in cancer cases than that in normal/benign cases.ConclusionCD109 increased cell proliferation rate and migration ability in post-sorted cervical cancer cell lines Caski and C4-1. On the contrary, CD109 knockdown reduced cell growth, migration and self-renewal capability in cervical cancer SiHa, Caski and C4-1 cells. Cervical carcinoma showed high expression of CD109 protein by IHC. Further in vivo and in vitro functional assays are essential to characterise the CD109-positive sub-population in cervical cancer which may provide more information of cervical CSCs-related properties and resistance of radiation therapy, with the underlying molecular mechanism involved.

Abstract 4187: Targeting the cytoskeleton protein ezrin sensitizes metastatic breast cancer cells to anthracycline based chemotherapy

Abstract The main cause of cancer-associated deaths is the spread of cancer cells to distant organ sites. Despite recent advances in treating primary tumors, modern chemotherapeutic strategies are relatively ineffective at treating metastasis, with clinical trials showing minimal improvements in overall survival for patients with metastatic disease. This is in large part due to chemotherapy resistance which remains a major clinical challenge limiting therapeutic responses for metastatic cancer patients. The cytoskeleton crosslinker protein ezrin has been shown to promote cancer metastasis in multiple preclinical models and is associated with poor prognosis in several cancer types, including breast cancer (BC). Ezrin also promotes pro-survival signaling, particularly in disseminated cancer cells, to facilitate metastatic outgrowth. However, whether ezrin plays a role in chemoresistance in BC is not yet known. In this study, we sought to determine whether ezrin can predict response to chemotherapy in BC patients and whether pharmacologic inhibition of ezrin alters the sensitivity of metastatic BC cells to anthracycline-based chemotherapy in preclinical models of metastasis. Ezrin protein expression was assessed in a BC patient cohort by tissue microarray immunohistochemistry (IHC) using the automated quantitative platform HaloTM. Among patients treated with systemic chemotherapy across all prognostic groups, high ezrin levels were associated with reduced disease-free, distant metastasis-free, as well as overall survival, compared to patients with lower ezrin levels. Next, we sought to determine whether targeting ezrin using a small molecule inhibitor (NSC668394) could enhance the efficacy of systemic doxorubicin treatment in vivo. Using an experimental lung metastasis model, we showed that the addition of NSC668394 sensitized metastatic BC cells to doxorubicin treatment, compared to either agent alone. We also tested the efficacy of these agents in targeting microscopic metastasis using neoadjuvant and adjuvant treatment models. Our results show that in both treatment modalities, NSC668394 or doxorubicin treatment alone was not able to reduce metastasis, however the addition of the ezrin inhibitor markedly sensitized metastases to doxorubicin and reduced overall lung metastatic burden. Taken together, our data suggest that ezrin may be a novel predictive marker of treatment response in BC patients and provide rationale for potential targeting of ezrin in patients with metastatic disease as an adjunct to chemotherapy. (Supported by OMPRN, CRS and BCAK). Citation Format: Victoria Hoskin, Abdi Ghaffari, Xiaolong Yang, Yolanda Madarnas, Sandip SenGupta, Sonal Varma, Peter A. Greer, Bruce E. Elliott. Targeting the cytoskeleton protein ezrin sensitizes metastatic breast cancer cells to anthracycline based chemotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4187.

Abstract 4040: α2β1 integrins are potential regulators of chemoresistance through modulation of biomechanical cues in pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor characterized by intrinsic or rapidly acquired chemoresistance. The remarkable desmoplastic response has been reported as a major contributor to chemoresistance, suggesting that PDAC progression could be highly influenced by mechanical factors (1). A recent study showed a key role of epithelial tension and matricellular fibrosis in the aggressiveness of SMAD4 mutant PDAC (2). Here we aimed at evaluating new mechanopharmacology approaches to overcome chemoresistance. PDAC cells attached to collagen and fibronectin showed a decreased sensitivity to chemotherapy, while the malignant phenotype was highly correlated to α2β1 integrin(ITGA2)-mediated adhesion to type I collagen (3). We hence hypothesized that this integrin might modulate chemoresistance. In two cohorts of 50 radically resected patients treated with gemcitabine, high expression of ITGA2 (assessed by immunohistochemistry in tissue-microarrays with 4 cores for each tumor) correlated to significantly shorter progression and overall free survival. Our hypothesis was further investigated in a gemcitabine-resistant clone (PANC1-R). In this clone, ITGA2 was among the top 10 most differentially upregulated genes at next-generation sequencing analysis. Using migration assays, we found that PANC1-R were more invasive than PANC1 cells, and a specific siRNA for ITGA2 caused a significant reduction of invasiveness while enhancing both gemcitabine antiproliferative effects and apoptosis induction. Using elastic micropillar arrays of varying stiffness (20-150kPa) (4), we observed delayed spreading of PANC1-R compared to PANC1 while a 24-hour treatment with a non-cytotoxic dose of gemcitabine activated traction forces in both lines, albeit to a lesser extent in PANC1-R. Remarkably, these cells showed also a significant increase of CXCR4 and MMP2 expression when growing in spheroids embedded in stiff collagen, as well as a different trend in modulation of E2F1 after exposure to gemcitabine, when growing as 2D collagen monolayers on soft and stiff flat PDMS, suggesting that aggressive/invasive behavior and response to gemcitabine are altered by both collagen and stiffness. These results define ITGA2 as a new prognostic factor, exerting its function through the promotion of metastatic behavior and altered drug response of PDAC cells under differential biomechanical conditions, which holds a potential as a novel therapeutic target to overcome PDAC resistance.

Abstract 4874: Receptor pharmacology and anti-cancer activity of selective DRD2/3 antagonist imipridone ONC206

Abstract Dopamine receptor D2 (DRD2) is a G protein-coupled receptor (GPCR) overexpressed in many cancers and its antagonism causes anti-tumor effects. ONC201, founding member of the imipridone class of small molecules, is a DRD2 antagonist in Phase II advanced cancer clinical trials. We evaluated the binding target and anti-tumor activity of ONC206, an ONC201 analog. An orphan small molecule target prediction algorithm revealed that ONC206, like ONC201, antagonizes DRD2. Experimental GPCR profiling using the PathHunter® β-Arrestin assay, confirmed that ONC206 selectively antagonizes D2-like (DRD2/3) but not D1-like (DRD 1/5) dopamine receptors. In this assay, ONC206 possesses a ~10-fold increased potency for DRD2 compared to ONC201 with a Ki of ~320nM with selectivity that was superior to approved antipsychotics. Shotgun mutagenesis across 350 amino acids of DRD2 identified 7 residues critical for ONC206-mediated antagonism of DRD2-induced calcium flux. Consistent with competitive inhibition, mutated residues were within the orthosteric binding site. While 6 mutated residues were also critical for ONC201 activity, one of the mutated residues was unique to ONC206, suggesting differentiated receptor pharmacology. TCGA analysis and immunohistochemistry of patient-derived tissue microarrays revealed DRD2 was overexpressed in neuroblastoma, sarcoma and pheochromocytoma specimens relative to normal tissues. In vitro profiling of ONC206 in the Genomic of Drug Sensitivity in Cancer collection of cell lines revealed broad nanomolar efficacy across most tumor types (GI50 &amp;lt;78-889nM) and ~5 to 20-fold improved potency relative to ONC201. Bone cancer and neuroblastoma were identified as the most ONC206-responsive solid tumor types that were comparatively less responsive to ONC201. Within bone cancer, Ewing's sarcoma (n=16) was most sensitive to ONC206 with nanomolar sensitivity (GI50 168-303nM) that was superior to ONC201. ONC206 was highly efficacious in neuroblastoma (n=35, GI50 87-589nM) including cell lines derived from metastatic sites and with MYCN amplification associated with poor prognosis. In the PC12 rat pheochromocytoma cell line ONC206 (GI50 200nM) was superior to ONC201. ONC206 time-course experiments revealed anti-cancer effects occurring at 48-72 post-treatment, similar to ONC201. In support of a wide therapeutic window, ONC206 reduced the viability of normal human fibroblasts at relatively high doses (GI50 &amp;gt; 5µM). Efficacy evaluation in the MHH-ES-1 Ewing's sarcoma xenograft model demonstrated that ONC206 (100 mg/kg PO every 10 days) causes significant tumor growth inhibition that was comparable to methotrexate (400 mg/kg, IP) while being better tolerated. Thus, imipridone ONC206 acts as a selective antagonist of DRD2/3 at nanomolar concentrations and may address tumor types where the properties of ONC201 do not permit for complete therapeutic engagement in vivo. Citation Format: Varun Vijay Prabhu, Neel Madhukar, Rohinton Tarapore, Mathew Garnett, Ultan McDermott, Cyril Benes, Neil Charter, Sean Deacon, Alexander VanEngelenburg, Joseph Rucker, Benjamin Doranz, Olivier Elemento, Wolfgang Oster, Martin Stogniew, Joshua Allen. Receptor pharmacology and anti-cancer activity of selective DRD2/3 antagonist imipridone ONC206 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4874.

Abstract 3748: p53 status as a determinant of functional duality of estrogen receptor beta in breast cancer: Therapeutic implications

Abstract Whether estrogen receptor beta (ERβ) is a pro- or anti-oncogenic protein in breast cancer has been controversial. ERβ levels are high in ERα negative cancers including triple-negative breast cancer (TNBCs). Recent reports including the Cancer Genome Atlas (TCGA) show that about 80% of TNBC express mutant p53 (mut-p53) and it is the most predominant driver in these cancers. We tested the hypothesis that p53 status in breast cancer will have an important role in determining the duality of ERβ functions. We have shown that ERβ directly binds to p53 in human breast cancer cells. Using glutathione-S-transferase (GST)-pull down and co-imunoprecipitation assays, we have delineated the domains of both proteins that are required for the ERβ-p53 interaction. The DNA binding domain (DBD) along with the hinge domain of ERβ and the C-terminal regulatory domain of p53 are essential for the interaction. Using the highly sensitive proximity ligation assay (PLA), we show ERβ-p53 interaction in situ in breast cancer cells expressing either wild type (wt)- or mut-p53. ERβ and p53 antibodies validated for specificity were used. In multiple cell lines, a combination of proliferation and apoptosis assays, RNAi technology, quantitative chromatin immunoprecipitation (qChIP), and quantitative real-time PCR (qRT-PCR) showed that ERβ is pro-proliferative in the context of wt-p53, whereas it is anti-proliferative in the context of mut-p53. The results were recapitulated in isogenic MDA-MB-231 TNBC cells (generated by CRISPR technology) that differ only in the presence of wt-versus mut-p53. ERβ binds and sequesters mut-p53 from mut-p53−p73 complex leading to reactivation of tumor suppressor p73. Consistent with these data, combination of immunohistochemistry (IHC) and PLA in TNBC patient tumor tissue microarray (TMA) showed that patients with tumors expressing wt-p53/ high ERβ had worse prognosis, both in terms of overall survival (OS) and progression-free survival (PFS). On the contrary, tumors expressing mut-p53/ high ERβ were of smaller size and stage. These findings were complemented by data from our analysis of the mut-p53 subgroup of the basal-like tumors in the METABRIC dataset which showed that patients with tumors expressing higher levels of ERβ RNA (ESR2) had better prognosis. Surprisingly, 4-Hyroxy Tamoxifen (Tam) increased ERβ-mut-p53 interaction in TNBC cells and combination of doxorubicin (Adriamycin) and Tam decreased the IC50 of doxorubicin by 10 fold leading to increased apoptosis. These data have significant clinical implications in targeting ERβ and mutant p53 signaling pathways for therapeutic purposes especially in ERα negative cancers such as TNBC. Importantly, although at present Tam is not standard of care for TNBC, our data suggest a possibility for repurposing Tam therapy alone or in combination with chemotherapy to treat TNBC stratified based on p53 status. Citation Format: Gokul M. Das, Utpal K. Mukhopadhyay, Christina Adams, Nadi Wickramasekera, Rajesh Medisetty, Sanjay Bansal, Laxmi Silwal-Pandit, Anne-Lise Borresen-Dale, Austin Miller, Wendy M. Sweizig, Angela Omilian, Wiam Bshara, Alka Mukhopadhyay. p53 status as a determinant of functional duality of estrogen receptor beta in breast cancer: Therapeutic implications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3748.

Abstract 2909: Development of new mechanism based therapeutic antibodies in non-small cell lung cancer

Abstract Lung cancer is second most common cancer in the world. Non Small Cell Lung Cancer (NSCLC) accounts approximately 80-85% of all lung cancer diagnosis. Traditional therapies of this disease were surgical resection, chemotherapy, and radiotherapy, alone or in combination. In addition, targeted therapeutic approach was based on the concept of discovering genetic alterations and the signaling pathways in cancer. Recently, to overcome the critical points for standard therapies, many groups were studied immunotherapeutic approaches, such as programed cell-death protein 1 (PD-1) antibody. However, rational use of these agents has been limited by the lack of a definitive predictive biomarker. Therefore, we identified new target, cancer immunotherapy related gene, CMG by shRNA libraries screening analysis on chemo-agents &amp; target therapy resistant non-small cell lung cancer cells. First of all, we investigated CMG expression by immunohistochemistry in various tissue microarray (TMA). These results show that CMG highly expressed in Lung cancer, Liver cancer, and gastric cancer. We investigated target potentials on lung cancer, liver cancer, and gastric cancer cell lines using in vitro and in vivo assay system. Knockdown of CMG by CMG shRNA was induced cell death in various cancer cell lines. In addition, suppression of CMG was induced tumor size regression in CMG shRNA stable cell lines-derived xenograft model. Based on these results, we synthesized a novel series of CMG therapeutic antibody. CMG therapeutic antibody is a lead antibody for treating Lung cancer patients who express CMG gene. These antibodies have anti-cancer effects and immunotherapeutic effects in lung cancer (NSCLC), liver cancer, and gastric cancer. In addition, the in vivo efficacy of CMG antibody was assessed in mouse lung cancer derived syngeneic mouse model. The CMG antibody was tri-daily i.p. injected and the tumor volume was measured and compared between groups. Dramatic tumor regression was observed in CMG antibody treated group. These results were shown that these antibodies have immunotherapeutic potentials. In conclusion, CMG is a promising target for Lung cancer patients (chemo-agents resistant or PD-1 resistant Lung cancer patienrts). Our antibodies can be promising therapeutic agents for lung cancer, Liver cancer, and gastric cancer. Citation Format: Jai-hee Moon, Dae Hee Lee, Jae-Sik Shin, Joseph Kim, Yoon Sun Park, Seung-Woo Hong, So Hee Lee, Mi Jin Kim, Joonyee Jung, Chun-Ho Park, Sun-Chul Hur, Hyojin Kim, Hyebin Park, Sang Soo Park, Jun Ki Hong, Ji Hee Gong, Jieun Kim, Hyun Ho Lee, Il-Whea Ku, Dong-Hoon Jin. Development of new mechanism based therapeutic antibodies in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2909.