Differential impact of cytoplasmic vs. nuclear RAD51 expression on breast cancer progression and patient prognosis

RAD51 recombinase is one of the DNA damage repair proteins associated with breast cancer risk. Apart from its function to maintain genomic integrity within the cell nucleus, RAD51 localized to the cytoplasm has also been implicated in breast malignancy. However, limited information exists on the roles of cytoplasmic vs. nuclear RAD51 in breast cancer progression and patient prognosis. In the present study, the association of cytoplasmic and nuclear RAD51 with clinical outcomes of patients with breast cancer was analyzed, revealing that elevated cytoplasmic RAD51 expression was associated with breast cancer progression, including increased cancer stage, grade, tumor size, lymph node metastasis and chemoresistance, along with reduced patient survival. By contrast, elevated nuclear RAD51 expression largely had the inverse effect. Results from in vitro investigations supported the cancer‑promoting effect of RAD51, showing that overexpression of RAD51 promoted breast cancer cell growth, chemoresistance and metastatic ability, while knockdown of RAD51 repressed these malignant behaviors. The current data suggest that differential expression of subcellular RAD51 had a distinct impact on breast cancer progression and patient survival. Specifically, cytoplasmic RAD51 in contrast to nuclear RAD51 was potentially an adverse marker in breast cancer.

Effect of esophageal cancer screening on mortality among patients with oral cancer and second primary esophageal cancer in Taiwan

OBJECTIVE

Oral and esophageal cancer are the fourth and fifth leading causes of cancer deaths among men in Taiwan. Despite a good prognosis for oral cavity cancer patients, survival is worse for those who develop second primary esophageal cancer. There remains no consensus regarding early prevention of potential second primary esophageal cancer in patients with oral cavity cancer. Our study aimed to compare 5-year mortality between endoscopically screened and non-screened patients with oral cavity cancer and second primary esophageal cancer.

MATERIALS AND METHODS

This study identified patients with incident oral cavity cancer and second primary esophageal cancer during 2004 and 2013 using the Taiwan Cancer Registry and National Health Insurance Research Database. We compared 5-year mortality from the second primary esophageal cancer diagnosis date between screened and non-screened groups of patients with oral cavity cancer and second primary esophageal cancer.

RESULTS

A total of 217 screened and 305 non-screened oral cavity cancer patients with second primary esophageal cancer were studied. Endoscopic screening significantly improved early detection of second primary esophageal cancer (adjusted odds ratio: 0.34, 95 % confidence interval [CI]: 0.23-0.49) and reduced all-cause mortality (adjusted hazard ratio: 0.80; 95 % CI: 0.66-0.98).

CONCLUSIONS

Oral cavity cancer patients with second primary esophageal cancer may have worse overall survival than those without. Early detection of second primary esophageal cancer is a crucial mediator between endoscopic screening and mortality. Endoscopic screening after the diagnosis of incident oral cavity cancer significantly increased early detection and reduced all-cause mortality.

A lesion-selective albumin-CTLA4Ig as a safe and effective treatment for collagen-induced arthritis

BACKGROUND

CTLA4Ig is a dimeric fusion protein of the extracellular domain of cytotoxic T-lymphocyte protein 4 (CTLA4) and an Fc (Ig) fragment of human IgG₁ that is approved for treating rheumatoid arthritis. However, CTLA4Ig may induce adverse effects. Developing a lesion-selective variant of CTLA4Ig may improve safety while maintaining the efficacy of the treatment.

METHODS

We linked albumin to the N-terminus of CTLA4Ig (termed Alb-CTLA4Ig) via a substrate sequence of matrix metalloproteinase (MMP). The binding activities and the biological activities of Alb-CTLA4Ig before and after MMP digestion were analyzed by a cell-based ELISA and an in vitro Jurkat T cell activation assay. The efficacy and safety of Alb-CTLA4Ig in treating joint inflammation were tested in mouse collagen-induced arthritis.

RESULTS

Alb-CTLA4Ig is stable and inactive under physiological conditions but can be fully activated by MMPs. The binding activity of nondigested Alb-CTLA4Ig was at least 10,000-fold weaker than that of MMP-digested Alb-CTLA4Ig. Nondigested Alb-CTLA4Ig was unable to inhibit Jurkat T cell activation, whereas MMP-digested Alb-CTLA4Ig was as potent as conventional CTLA4Ig in inhibiting the T cells. Alb-CTLA4Ig was converted to CTLA4Ig in the inflamed joints to treat mouse collagen-induced arthritis, showing similar efficacy to that of conventional CTLA4Ig. In contrast to conventional CTLA4Ig, Alb-CTLA4Ig did not inhibit the antimicrobial responses in the spleens of the treated mice.

CONCLUSIONS

Our study indicates that Alb-CTLA4Ig can be activated by MMPs to suppress tissue inflammation in situ. Thus, Alb-CTLA4Ig is a safe and effective treatment for collagen-induced arthritis in mice.

Fumarate hydratase inhibits non-small cell lung cancer metastasis via inactivation of AMPK and upregulation of DAB2

Lung cancer is one of the leading causes of cancer mortality worldwide. As it is often first diagnosed only when cancer metastasis has already occurred, the development of effective biomarkers for the risk prediction of cancer metastasis, followed by stringent monitoring and the early treatment of high-risk patients, is essential for improving patient survival. Cancer cells exhibit alterations in metabolic pathways that enable them to maintain rapid growth and proliferation, which are quite different from the metabolic pathways of normal cells. Fumarate hydratase (FH, fumarase) is a well-known tricarboxylic acid cycle enzyme that catalyzes the reversible hydration/dehydration of fumarate to malate. The current study sought to investigate the relationship between FH expression levels and the outcome of patients with lung cancer. FH was knocked down in lung cancer cells using shRNA or overexpressed using a vector, and the effect on migration ability was assessed. Furthermore, the role of AMP-activated protein kinase (AMPK) phosphorylation and disabled homolog 2 in the underlying mechanism was investigated using an AMPK inhibitor approach. The results showed that in lung cancer tissues, low FH expression was associated with lymph node metastasis, tumor histology and recurrence. In addition, patients with low FH expression exhibited a poor overall survival in comparison with patients having high FH expression. When FH was overexpressed in lung cancer cells, cell migration was reduced with no effect on cell proliferation. Furthermore, the level of phosphorylated (p-)AMPK, an energy sensor molecule, was upregulated when FH was knocked down in lung cancer cells, and the inhibition of p-AMPK led to an increase in the expression of disabled homolog 2, a tumor suppressor protein. These findings suggest that FH may serve as an effective biomarker for predicting the prognosis of lung cancer and as a therapeutic mediator.

CD44 Mediates Oral Squamous Cell Carcinoma-Promoting Activity of MRE11 via AKT Signaling

Oral cancer is one of the highest-incidence malignancies worldwide, with the occurrence of oral squamous cell carcinoma (OSCC) being the most frequently diagnosed form. A barrier for oral cancer management may arise from tumor cells that possess properties of cancer stemness, which has been recognized as a crucial factor in tumor recurrence and metastasis. As such, understanding the molecular mechanisms underlying these tumor cells may provide insights for improving cancer treatment. MRE11 is the core protein of the RAD50/MRE11/NBS1 complex with a primary role in DNA damage repair, and it has been diversely associated with tumor development including OSCC. In this study, we aimed to investigate the engagement of CD44, a cancer stemness marker functioning in the control of cell growth and motility, in OSCC malignancy under the influence of MRE11. We found that overexpression of MRE11 enhanced CD44 expression and tumorsphere formation in OSCC cells, whereas knockdown of MRE11 reduced these phenomena. In addition, the MRE11-promoted tumorsphere formation or cell migration ability was compromised in OSCC cells carrying siRNA that targets CD44, as was the MRE11-promoted AKT phosphorylation. These were further supported by analyzing clinical samples, where higher CD44 expression was associated with lymph node metastasis. Additionally, a positive correlation between the expression of MRE11 and CD44, or that of CD44 and phosphorylated AKT, was observed in OSCC tumor tissues. Finally, the expression of CD44 was found to be higher in the metastatic lung nodules from mice receiving tail vein-injection with MRE11-overexpressing OSCC cells compared with control mice, and a positive correlation between CD44 and phosphorylated AKT was also observed in these metastatic lung nodules. Altogether, our current study revealed a previously unidentified mechanism linking CD44 and AKT in MRE11-promoted OSCC malignancy, which may shed light to the development of novel therapeutic strategies in consideration of this new pathway in OSCC.

Fabrication of 3D Amino-Functionalized Metal-Organic Framework on Porous Nickel Foam Skeleton to Combinate Follicle Stimulating Hormone Antibody for Specific Recognition of Follicle-Stimulating Hormone

In this study, a superficial and highly efficient hydrothermal synthesis method was developed for the in situ growth of amine-functionalized iron containing metal-organic frameworks (H2N-Fe-MIL-101 MOFs) on porous nickel foam (NicF) skeletons (H2N-Fe-MIL-101/NicF). The uniform decoration of the H2N-Fe-MIL-101 nanosheets thus generated on NicF was immobilized with follicle-stimulating hormone (FSH) antibody (Ab-FSH) to detect FSH antigen. In the present work, the Ab-FSH tagged H2N-Fe-MIL-101/NicF electrode was first applied as an immunosensor for the recognition of FSH, electrochemically. With all of the special characteristics, this material demonstrated superior specific recognition and sensitivity for FSH with an estimated detection limit (LOD) of 11.6 and 11.5 fg/mL for buffered and serum solutions, respectively. The availability of specific functional groups on MOFs makes them an interesting choice for exploring molecular sensing applications utilizing Ab-FSH tagged biomolecules.

Decreased Circulating Melatonin with Loss of Age-Related Biphasic Change in Patients with Oral Squamous Cell Carcinoma

Background: Melatonin, produced by the pineal gland, is known for its antioxidant, oncostatic, and anti-inflammatory properties. However, studies on serum melatonin levels in different cancer types have yielded conflicting results, and little is known about the clinical significance of serum melatonin in oral squamous cell carcinoma (OSCC) in the Southern Asian population. Therefore, we explored its role in OSCC in this study. Methods: A total of 67 male OSCC patients and 78 healthy controls were enrolled in this case–control study. The serum levels of melatonin were determined by enzyme-linked immunosorbent assay (ELISA) and compared between the two groups. Results: The serum melatonin levels were significantly lower in OSCC patients compared with healthy controls (mean ± standard deviation, 15.0 ± 4.6 vs. 18.5 ± 11.8 pg/mL, p = 0.02). In the subgroup of age less than 55 years (mean age of OSCC), OSCC patients had a significantly decreased melatonin level than healthy controls (mean melatonin, 15.7 ± 12.6 vs. 20.8 ± 3.9 pg/mL, p = 0.02). Decreased serum melatonin (odds ratio (OR): 0.95, 95%CI: 0.91–0.99), alcohol consumption (OR: 29.02, 95%CI: 11.68–72.16), betel quid chewing (OR:136.44, 95%CI: 39.17–475.27), and cigarette smoking (OR:29.48, 95%CI: 11.06–78.60) all increased the risk of OSCC under univariate analyses of logistic regression. Betel quid chewing (OR: 45.98, 95%CI: 10.34–204.49) and cigarette smoking (OR:6.94, 95%CI: 1.60–30.16) were the independent risk factors for OSCC in Taiwan. In addition, a negative correlation between age and melatonin level was observed in healthy controls (Pearson r = −0.24, p = 0.03). However, the negative correlation was lost in patients with OSCC. Melatonin concentration had no association with the severity of OSCC. Conclusion: Overall, our study provides evidence that serum melatonin levels decreased in OSCC patients in Taiwan and the decreased level is much significant in young populations and suggests that the decreased melatonin was associated with OSCC, especially in young populations. Further studies are warranted to investigate whether melatonin can be a useful non-invasive screening tool for OSCC.

CD44 Promotes Lung Cancer Cell Metastasis through ERK-ZEB1 Signaling

Lung cancer is a malignancy with high mortality worldwide, and metastasis occurs at a high frequency even when cancer spread is not detectable at primary operation. Cancer stemness plays an important role in malignant cancer behavior, treatment resistance, and cancer metastasis. Therefore, understanding the molecular pathogenesis behind cancer-stemness-mediated metastasis and developing effective approaches to prevent metastasis are key issues for improving cancer treatment. In this study, we investigated the role of CD44 stemness marker in lung cancer using in vitro and clinical studies. Immunohistochemical staining of lung cancer tissue specimens revealed that primary tumors with higher CD44 expression showed increased metastasis to regional lymph nodes. Flow cytometry analysis suggested that CD44 positive cells were enriched in the metastatic lymph nodes compared to the primary tumors. CD44 overexpression significantly increased migration and invasion abilities of lung cancer cells through CD44-induced ERK phosphorylation, ZEB1 upregulation, and Claudin-1 downregulation. Furthermore, ERK inhibition suppressed the migration and invasion abilities of CD44-overexpressing lung cancer cells. In summary, our in vitro and clinical results indicate that CD44 may be a potential prognostic and therapeutic marker for lung cancer patients.

Visfatin Enhances Breast Cancer Progression through CXCL1 Induction in Tumor-Associated Macrophages

Visfatin, an adipocytokine highly expressed in breast tumor tissues, is associated with breast cancer progression. Recent studies showed that adipocytokines mediate tumor development through adipocytokine tumor-stromal interactions in the tumor microenvironment. This study focused on the interaction between one key stromal constituent-tumor-associated macrophages-and visfatin. Pretreatment of THP-1 and peripheral blood mononuclear cells (PBMCs) with recombinant visfatin resulted in M2-polarization determined by CD163 and CD206 expression. Indirect co-culture with visfatin-treated THP-1 (V-THP-1) promoted the viability, migration, tumorsphere formation, EMT, and stemness of breast cancer cells. Cytokine array identified an increased CXCL1 secretion in V-THP-1 conditioned medium and recombinant CXCL1 enhanced cell migration and invasion, which were abrogated by the CXCL1-neutralizing antibody. Additionally, visfatin induced pERK in THP-1 cells and clinical samples confirmed a positive CXCL1/pERK correlation. In an orthotopic mouse model, the tumor bioluminescent signal of luciferase-expressing MDA-MB-231 (Luc-MDA-MB-231) cells co-cultured with V-THP-1 and the expression of proliferation marker Ki67 were significantly higher than that co-cultured with THP-1. Furthermore, tail vein-injected Luc-MDA-MB-231 pretreated with V-PBMCs conditioned medium metastasized to lungs more frequently compared to control, and this was reversed by CXCL1 blocking antibody. In summary, this study demonstrated that visfatin enhanced breast cancer progression via pERK/CXCL1 induction in macrophages.

Low Dose Combined Treatment with Ultraviolet-C and Withaferin a Enhances Selective Killing of Oral Cancer Cells

Withaferin A (WFA), a Withania somnifera-derived triterpenoid, is an anticancer natural product. The anticancer effect of nonionizing radiation such as ultraviolet-C (UVC) as well as the combined treatment of UVC and WFA is rarely investigated. Low dose UVC and/or WFA treatments (12 J/m² and/or 1 μM) were chosen to evaluate antioral cancer cell line effects by examining cytotoxicity, cell cycle disruption, apoptosis induction, and DNA damage. For two cancer cell lines (Ca9-22 and HSC-3), single treatment (UVC or WFA) showed about 80% viability, while a combined treatment of UVC/WFA showed about 40% viability. In contrast, there was noncytotoxicity to normal oral cell lines (HGF-1). Compared to single treatment and control, low dose UVC/WFA shows high inductions of apoptosis in terms of flow cytometric detections for subG1, annexin V, pancaspase changes as well as Western blotting for detecting cleaved poly (ADP-ribose) polymerase (c-PARP) and caspase 3 (c-Cas 3) and luciferase assay for detecting Cas 3/7 activity. Low dose UVC/WFA also showed high inductions of oxidative stress and DNA damage in terms of flow cytometric detections of reactive oxygen species (ROS), mitochondrial superoxide (MitoSOX) generation, and membrane potential (MitoMP) destruction, γH2AX and 8-oxo-2’deoxyguanosine (8-oxodG) types of DNA damages. For comparison, low dose UVC/WFA show rare inductions of annexin V, Cas 3/7 activity, ROS, MitoSOX, and MitoMP changes to normal oral HGF-1 cells. Therefore, low dose UVC/WFA provides a novel selectively killing mechanism to oral cancer cells, suggesting that WFA is a UVC sensitizer to inhibit the proliferation of oral cancer cells.

Low Concentration of Withaferin a Inhibits Oxidative Stress-Mediated Migration and Invasion in Oral Cancer Cells

Withaferin A (WFA) has been reported to inhibit cancer cell proliferation based on high cytotoxic concentrations. However, the low cytotoxic effect of WFA in regulating cancer cell migration is rarely investigated. The purpose of this study is to investigate the changes in migration and mechanisms of oral cancer Ca9-22 cells after low concentrations of WFA treatment. WFA under 0.5 μM at 24 h treatment shows no cytotoxicity to oral cancer Ca9-22 cells (~95% viability). Under this condition, WFA triggers reactive oxygen species (ROS) production and inhibits 2D (wound healing) and 3D cell migration (transwell) and Matrigel invasion. Mechanically, WFA inhibits matrix metalloproteinase (MMP)-2 and MMP-9 activities but induces mRNA expression for a group of antioxidant genes, such as nuclear factor, erythroid 2-like 2 (NFE2L2), heme oxygenase 1 (HMOX1), glutathione-disulfide reductase (GSR), and NAD(P)H quinone dehydrogenase 1 (NQO1)) in Ca9-22 cells. Moreover, WFA induces mild phosphorylation of the mitogen-activated protein kinase (MAPK) family, including extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and p38 expression. All WFA-induced changes were suppressed by the presence of ROS scavenger N-acetylcysteine (NAC). Therefore, these results suggest that low concentration of WFA retains potent ROS-mediated anti-migration and -invasion abilities for oral cancer cells.

Orabase-Formulated Benzalkonium Chloride Effectively Suppressed Oral Potentially Malignant Disorder In Vitro and In Vivo

Oral potentially malignant disorder (OPMD) is associated with an increased risk of progression to oral cancer. Patients with dysplastic changes of the precancerous lesions have a higher malignant transformation rate than those without dysplastic changes. Radiotherapy and surgery are the traditionally preferred choices for OPMD treatment. However, side effects caused by radiotherapy and surgery may reduce the willingness of patients to accept therapy. Therefore, developing an Orabase-formulated drug, which can be non-invasively administered, may provide an alternative treatment choice. To find, verify, and develop a new anti-cancer drug cost a lot of time and money, while drug repurposing can shorten both time and cost. In this study, we utilized high-throughput screening library to identify clinical drugs, which may have new bioactivities. Herein, we report that benzalkonium chloride (BAK), an antimicrobial preservative for pharmaceutical products, significantly induced reactive oxygen species production and cell death in oral precancerous cells. Additionally, our results showed that phosphorylation of STAT3 (Tyr705) and Akt (Ser473) were involved in cell death caused by BAK in DOK cells. According to animal studies, the development of DMBA-induced oral precancerous lesions was inhibited by 2% BAK. In conclusion, Orabase-formulated BAK may be a potential treatment for OPMD in the future.

Abstract 1608: Resistin promotes cancer progression through induction of mesenchymal phenotypes and stem cell-like properties in breast cancer

Growing evidence indicates that resistin plays a role in insulin resistance, obesity, inflammation, coronary artery disease, atherosclerosis and malignancies. In this study, we have explored the effects and mechanisms of resistin in promoting breast cancer progression. High serum resistin levels were positively correlated with tumor stage, tumor size and lymph node metastasis in breast cancer patients. Resistin treatment modulated the expression of epithelial-mesenchymal transition (EMT) regulators and enhanced the migratory, invasive and anti-anoikis activities in breast cancer cells. Additionally, resistin treatment promoted the formation of mammospheres and the expression of pluripotency factors (sox2, nanog and oct4). STAT3 specific inhibitor, stattic, was able to abolish the resistin mediated enhancements of cell motilities and stem cell-like properties. Using in vivo model, we found that resistin markedly enhance metastasis and tumor growth. Taken together, our data clearly demonstrated that resistin promotes cancer progression through induction of EMT and stemness by activating TLR4/STAT3 signaling in breast cancer.

Citation Format: Shyng-Shiou F. Yuan, Chie-Hong Wang. Resistin promotes cancer progression through induction of mesenchymal phenotypes and stem cell-like properties in breast cancer. [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 1608.

Abstract 3011: Two-sided story of DNA repair proteins MRE11 and RAD51 in breast cancer

Background

DNA repair proteins are required for the maintenance of genome integrity in normal cells. However previous studies also showed that altered expression of MRE11 and RAD51, proteins crucial for DNA double-strand break repair, DNA replication, and telomere maintenance, are associated with cancer outcomes. In this study, we investigated the role of MRE11 and RAD51 in breast cancer in both clinical and in vitro settings.

Methods

The expression of MRE11 and RAD51 in breast tumor tissues were determined by immunohistochemistry, and associations with clinicopathological characteristics and overall survival were assessed using Cox proportional hazards regression models and Kaplan-Meier survival curves. The effect of altered expression of MRE11 and RAD51 on cell proliferation, invasion, and treatment resistance was assessed in vitro using breast cancer cell lines, with the underlying mechanisms explored. The effect of MRE11 and RAD51 overexpression on tumor growth was assessed in an orthotopic xenograft model. All statistical tests were two-sided.

Results

High MRE11 expression was statistically significantly associated with malignant cancer behaviors including increased tumor size and lymph node metastasis as well as resistance to radiotherapy and chemotherapy. MRE11 overexpression in breast cancer cell lines promoted cell proliferation through STAT3, cell cycle entry, invasion and migration, and radioresistance via enhanced DNA repair activity, and also inhibited apoptosis; knockdown of MRE11 had the opposite effect. In xenograft tumor-bearing mice, tumor growth was increased in MRE11-overexpressing group.

RAD51 was expressed both in the cytoplasm and nucleus of all the breast cancer and non-cancerous cell lines. Expression levels of cytoplasmic RAD51 were positively correlated with cancer stage, tumor size, lymph node metastasis in breast cancer patients. High expression of cytoplasmic RAD51 predicted a poor patient survival as well as resistance to radiotherapy and chemotherapy.

Conclusion

High MRE11 and RAD51 expression was associated with a more malignant behavior in breast cancer. MRE11 and RAD51 may serve as potential targets for therapeutic intervention against breast cancer.

Note: This abstract was not presented at the meeting.

Citation Format: Shyng-Shiou F. Yuan, Amos Hung, Ming-Feng Hou. Two-sided story of DNA repair proteins MRE11 and RAD51 in breast cancer. [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 3011. doi:10.1158/1538-7445.AM2015-3011

Abstract 434: Circulating visfatin promotes malignant cancer behavior through activation of STAT3 signaling in breast cancer

Adipocytokines are adipocyte-derived hormones which have been shown potentially associated with carcinogenesis. In this study, the role of circulating visfatin, a recently discovered adipocytokine involving in breast cancer progression, was investigated. Our data showed that the levels of serum visfatin in breast cancer patients were closely correlated with several clinicopathological characteristics including tumor stages, tumor size, and lymph node (LN) metastasis. In addition, differential association of disease recurrence and patients survival with hormone receptors such as estrogen receptor (ER), progesterone receptor (PR), and epidermal growth factor receptor 2 (Her2/Neu) were observed. Patients with high serum visfatin, especially in combination with ER- status, showed the lowest survival rate. Furthermore, high serum visfatin patients had a lower recurrence risk and better patient survival after adjuvant hormone therapy. Notably, serum visfatin was positively associated with STAT3 activation through tyrosine phosphorylation in breast cancer tissues. In agreement with the clinical observation, our in vitro data revealed that breast cancer cells treated with visfatin not only enhanced cell proliferation but also activated STAT3 and its upstream regulator, JAK1. Moreover, inhibition of STAT3 resulted in the reduced cell proliferation and invasive ability of breast cancer cells. In conclusion, we propose that high levels of circulating visfatin, probably via activation of STAT3 signaling pathway, lead to a malignant cancer progression and poor survival of breast cancer patients. Therefore, the visfatin/STAT3 pathway may constitute a valuable prognostic system for breast cancer patients. In addition, interference of the visfatin/STAT3 signaling may represent a novel therapeutic potential in the treatment of breast cancer.

Table 1. Univariate and multivariable analysis of overall survival for breast cancerVariablesItemUnivariateMultivariable†Hazard Rate Ratio95% Confidence intervalP valueHazard Rate Ratio95% Confidence intervalP valueTumor size (cm)>54.36(1.69,11.27)0.0022.13(0.79,5.74)0.1362-52.47(1.05,5.81)0.0391.68(0.70,4.05)0.245<21.001.00LN Metastasis≥23.34(1.75,6.37)<0.0012.43(1.25,4.72)0.0090-11.001.00GradeIII2.47(0.81,7.53)0.112---II1.56(0.53,4.55)0.419--I1.00-Age(y)>501.49(0.81,2.73)0.197---≤501.00-BMI(kg/m2)<241.14(0.60,2.14)0.690---≥241.00-Her2/NeuPositive1.14(0.60,2.17)0.699---Negative1.00-RadiotherapyYes1.11(0.60,2.03)0.744---No1.00-ChemotherapyYes0.89(0.41,1.93)0.774---No1.00-HormoneTherapyYes0.36(0.20,0.66)0.0010.46(0.24,0.87)0.017No1.001.00VisfatinHigh5.67(2.01,15.98)0.0013.55(1.22,10.36)0.020Low1.001.00† Variables with P values greater than 0.10 in the univariate analysis were excluded from multivariable analysis.

Citation Format: Shyng-Shiou F. Yuan, Amos C. Hung, Ming-Feng Hou. Circulating visfatin promotes malignant cancer behavior through activation of STAT3 signaling in breast 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 434. doi:10.1158/1538-7445.AM2014-434

Abstract 1933: Visfatin promotes malignant breast cancer behavior through activation of STAT3

Background. Obesity-associated adipocyte dysfunction and adipocytokine imbalance has become a major focus in breast cancer research. In this study, the role of circulating visfatin, a recently discovered adipocytokine, in breast cancer was explored.

Methods. Serum visfatin was analyzed by enzyme-linked immunosorbent assay and correlated with clinicopathological characteristics and survival, while the expression of phosphorylated and activated STAT3 in breast cancer tissue was analyzed by immunohistochemistry. The biologic activity of visfatin as well as the underlying mechanisms was analyzed by using XTT cell proliferation assay, flow cytometry and immunoblotting analysis in human breast cancer cells.

Results. Serum visfatin was substantially elevated in breast cancer patients. It was positively associated with tumor stage and lymph node metastasis, but negatively associated with estrogen receptor (ER) and progesterone receptor (PR) status. Breast cancer patients with high serum visfatin, especially in combination with ER− and PR− status, had a poor patient survival. On the other hand, patients with high serum visfatin had a lower incidence of disease recurrence and a better patient survival after adjuvant hormone therapy. Serum visfatin was positively associated with STAT3 tyrosine phosphorylation in breast cancer tissues. In agreement with the clinical observation, visfatin treatment in breast cancer cells activated JAK1 and SRC as well as their downstream molecule STAT3, followed by an enhanced G1/S progression and cell proliferation.

Conclusion. Serum visfatin, through activation of STAT3, leads to a malignant cancer behavior and poor survival in breast cancer patients.

Key words: visfatin, adipocytokine, breast cancer, STAT3

Citation Format: Shyng-Shiou F. Yuan, Yun-Ju Chen, Yi-Chen Lee, Ming-Feng Hou. Visfatin promotes malignant breast cancer behavior through activation of STAT3. [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 1933. doi:10.1158/1538-7445.AM2013-1933

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.