The long noncoding RNA ANRIL has been found to be abnormally expressed and play important roles in different cancers. However, the expression and function of ANRIL in acute myeloid leukemia (AML) remain to be declared. In this study, we found that ANRIL is up-regulated in AML patients at diagnosis and down-regulated in patients after complete remission (CR). Functional studies showed that knockdown of ANRIL expression resulted in a decline in glucose uptake and inhibition of AML cell maintenance in vitro and in vivo. Mechanically, ANRIL was found to repress the expression of Adiponectin receptor (AdipoR1), a key regulator of glucose metabolism. Both ANRIL and AdipoR1 knockdown reduced the expression levels of phosphorylation of AMPK and SIRT1, implying a previously unappreciated ANRIL-AdipoR1-AMPK/SIRT1 signaling pathway in regulating cell glucose metabolism and survival in AML. The study is the first to demonstrate that ANRIL promotes malignant cell survival and cell glucose metabolism to accelerate AML progression and is a potential prognostic marker and therapeutic target in AML treatment.

Adiponectin is the most abundant adipokine in the tumor microenvironment. The role of this protein in tumor progression, however, remains controversial. In the present study, we aimed to investigate the effects of adiponectin on the abilities of migration and invasion in non‑small cell lung carcinoma (NSCLC). Using NSCLC cell lines, we examined the effects of adiponectin on cell migration and invasion using Transwell assays. Expression of epithelial‑mesenchymal transition markers was examined via microscopy and western blotting. We also performed a knockdown of Twist, AdipoR1 and AdipoR2 in NSCLC cells with siRNAs. The addition of adiponectin to NSCLC cells inhibited both the migration and invasion abilities. Furthermore, we found that NSCLC cells displayed increased epithelial marker expression and downregulation of mesenchymal marker expression following adiponectin administration. Twist AdipoR1 and AdipoR2 knockdown reversed the inhibitory effects of adiponectin on migration and invasion in NSCLC and epithelial‑mesenchymal transition. Exogenous adiponectin significantly impaired the migratory and invasive capacities of NSCLC cells through reversal of EMT, suggesting that adiponectin may be a novel promising therapeutic approach against NSCLC.

BACKGROUND: Obesity is closely associated with colorectal cancer (CRC), but the underlying mechanism is unclear. We thus evaluated the expression of the adipokine gene family in CRC tissues and its clinicopathological implications.
METHODS: Correlations between the mRNA expression levels of the adipokine gene family (ADIPOQ, ADIPOR1/2, LEP, LEPR, RETN, RETNLB, RBP4, SFRP5, NAMPT, and SPP1) in CRC tissue and clinicopathologic factors were analyzed using data from The Cancer Genome Atlas database.
RESULTS: Tissue samples from 369 patients were analyzed, and 82 deaths occurred during follow-up (median, 670 days). Overall, mortality was associated with positive venous invasion, higher TNM stage, and increased ADIPOR1 (adiponectin receptor 1 gene) and SPP1 (secreted phosphoprotein gene 1) mRNA expression. Higher ADIPOR1 (odds ratio [OR]: 3.29, 95% confidence interval [CI]: 1.33-8.13) and SPP1 (OR: 2.31, 95%CI: 1.49-3.59) levels were independently associated with increased mortality. A Kaplan-Meier survival analysis showed shorter overall survival times in patients with higher ADIPOR1 (P = 0.006) and SPP1 (P < 0.001) expression.
CONCLUSIONS: Upregulation of ADIPOR1 and SPP1, among the adipokine gene family, in cancer tissue is associated with poor survival in CRC, suggesting a potential mechanism linking obesity and CRC. ADIPOR1 and SPP1 expression could become useful prognostic indicators after further validation.

BACKGROUND: The role of adopokines in adrenal tumors' hormonal activity remains unclear. Obesity may induce arterial hypertension, disorders of carbohydrate metabolism, and is a risk factor of cardiovascular disease. In patients with subclinical hormone secretion by the adrenal cortex or medulla the risk of metabolic disease is increased.
OBJECTIVE: Authors of this retrospective study selected 78 patients with subclinical hormone secretion out of all adrenal incidentaloma patients hospitalized in the Department of Endocrinology and Internal Medicine between 1995 and 2014.
METHODS: The analyzed group comprised of 38 subclinical Cushing's syndrome (SCS), 40 incidentally discovered pheochromocytoma (PHEO) and 42 patients operated due to an adrenal tumor without pathological hormonal activity. Expression of adiponectin (AdipoR1, AdipoR2) and leptin (Ob-R) receptors in adrenal tumors was assessed in relation to body mass index (BMI) and hormonal activity.
RESULTS: We found statistically significant negative correlations between BMI and expression of all examined receptors in SCS patients (AdipoR1: p= 0.032; AdipoR2: p< 0.001; leptin Ob-R: p= 0.001). In PHEOs, BMI correlated negatively only with AdipoR2 (p= 0.014).
CONCLUSIONS: Data obtained show that the most significant factor associated with the expression of AdipoR1, AdipoR2 and leptin Ob-R receptors in the adrenal tumor tissue is BMI, not their hormonal activity.

The expression of adiponectin receptors AdipoR1 and AdipoR2 has been reported in the human ovary and ovarian cancer tissues. Moreover, adiponectin has been reported to act as an anti-tumor factor by inhibiting cancer cell proliferation. Thus, we investigate whether adiponectin and its receptors influence ovarian cancer development. In the present study, we found that adiponectin was not expressed in the granulosa cell line (COV434), and epithelial ovarian cancer cell lines (OVCAR-3, SKOV-3, and Caov-3). Additionally, we found that AdipoR1 and AdipoR2 expression is lower in epithelial ovarian cancer cells than in granulosa tumor cells. Endogenous 17β-estradiol as well as exogenous estrogens, such as bisphenol A and its chlorinated and brominated analogs do not affect adiponectin receptor expression. We found that adiponectin inhibited the growth of OVCAR-3 and SKOV-3 cells, and that this effect was independent of apoptosis. Moreover, adiponectin reverses the stimulatory effects of 17β-estradiol and insulin-like growth factor 1 on cell proliferation by downregulating the expression of their receptors, whereas progesterone increased the sensitivity of cancer cells to adiponectin by upregulating AdipoR1 and AdipoR2 expression. These results suggest interactions between adiponectin and various ovarian steroid hormone and growth factor pathways in ovarian cancer cells.

The development of breast cancer is influenced by the adipose tissue through the proteins leptin and adiponectin. However, there is little research concerning AdipoR1 and AdipoR2 receptors and the influence of leptin over them. The objective of this work was to analyze the expression of AdipoR1 and AdipoR2, modulated by differential concentrations of leptin in an obesity model (10 ng/mL, 100 ng/mL, and 1000 ng/mL) associated with breast cancer in MCF-7 and HCC1937 cell lines. Each cell line was characterized through immunohistochemistry, and the expression of AdipoR1 and AdipoR2 was analyzed by PCR in real time using TaqMan® probes. Leptin induced an increase in cell population of MCF-7 (23.8%, 10 ng/mL, 48 h) and HCC1937 (17.24%, 1000 ng/mL, 72 h). In MCF-7, the expression of AdipoR1 decreased (3.81%, 1000 ng/mL) and the expression of AdipoR2 increased by 13.74 times (10 ng/mL) with regard to the control. In HCC1937, the expression of AdipoR1 decreased by 86.28% (10 ng/mL), as well as the expression of AdipoR2 (50.3%, 100 ng/mL). In regard to the results obtained, it could be concluded that leptin has an effect over the expression of AdipoR1 and AdipoR2 mRNA.

Developing a system of molecular subtyping for endometrial tumors might improve insight into disease etiology and clinical prediction of patient outcomes. High body mass index (BMI) has been implicated in development of endometrial cancer through hormonal pathways and might influence tumor expression of biomarkers involved in BMI-sensitive pathways. We evaluated whether endometrial tumor expression of 7 markers from BMI-sensitive pathways of insulin resistance could effectively characterize molecular subtypes: adiponectin receptor 1, adiponectin receptor 2, leptin receptor, insulin receptor (beta subunit), insulin receptor substrate 1, insulin-like growth factor 1 receptor, and insulin-like growth factor 2 receptor. Using endometrial carcinoma tissue specimens from a case-only prospective sample of 360 women from the Nurses' Health Study, we scored categorical immunohistochemical measurements of protein expression for each marker. Logistic regression was used to estimate associations between endometrial cancer risk factors, especially BMI, and tumor marker expression. Proportional hazard modeling was performed to estimate associations between marker expression and time to all-cause mortality as well as time to endometrial cancer-specific mortality. No association was observed between BMI and tumor expression of any marker. No marker was associated with time to either all-cause mortality or endometrial cancer-specific mortality in models with or without standard clinical predictors of patient mortality (tumor stage, grade, and histologic type). It did not appear that any of the markers evaluated here could be used effectively to define molecular subtypes of endometrial cancer.

Mutations and translocations within the COMPASS (complex of proteins associated with Set1) family of histone lysine methyltransferases are associated with a large number of human diseases, including cancer. Here we report that SET1B/COMPASS, which is essential for cell survival, surprisingly has a cytoplasmic variant. SET1B, but not its SET domain, is critical for maintaining cell viability, indicating a novel catalytic-independent role of SET1B/COMPASS. Loss of SET1B or its unique cytoplasmic-interacting protein, BOD1, leads to up-regulation of expression of numerous genes modulating fatty acid metabolism, including

Recent studies have shown that miRNAs play vital roles in tumorigenesis. However, their effects on the epithelial-mesenchymal transition (EMT) in hepatocellular carcinoma (HCC) need to be better understood. Our present study demonstrates that miR-221, which is overexpressed in HCC tissues, promotes EMT in HCC cell lines by targeting a new gene, AdipoR1. First, overexpression of miR-221 was identified in 40 pairs of human HCC tumor and matched normal tissues. Moreover, we found that elevated miR-221 was strongly associated with worse clinicopathologic features in HCC patients. Next, the loss of miR-221 inhibited, but its restoration enhanced, the EMT process in HCC cell lines. Furthermore, bioinformatics software predicted that AdipoR1 would be a direct target of miR-221. We then observed negative regulation of miR-221 on AdipoR1 protein expression, and direct binding between them was further verified using dual-luciferase assays. In addition, knockdown of AdipoR1 resulted in promotion of the EMT in HCC cells, and AdipoR1 overexpression reversed the miR-221-induced EMT. Lastly, we found that the JAK/STAT3 pathway may be involved in the AdipoR1-mediated EMT process. In conclusion, miR-221 acts as a promoter of the EMT process in HCC cells by targeting AdipoR1, and this study highlights the potential effects of miR-221 on the prognosis and treatment of HCC.

A prospective method of treatment for cancer is to inhibit oncogene signaling pathways with microRNA (miRNA or miR). In the present study, whether the expression of STAT2, AdipoR1/AMPK/SIRT1 pathway of glioma is regulated by miR-3908 was explored. To confirm whether the predicted miR-3908 is matched with STAT2 and AdipoR1, 3'UTR luciferase activity of STAT2 and AdipoR1 was assessed. In the presence of the mimics or inhibitors of miR-3908, cell function of glioma cells, such as proliferation, growth, migration, invasion and apoptosis were analyzed. The expression of AdipoR1 and its downstream AMPK/SIRT1 pathway proteins or STAT2 were examined. Luciferase reporter analysis showed that miR-3908 directly target STAT2 and AdipoR1. miR-3908 suppressed expression of STAT2 or AdipoR1 and downregulated AdipoR1 pathway genes, including AMPK, p-AMPK and SIRT1. miR-3908 inhibited tumorigenicity, migration, growth and invasion in glioma cell lines U251 and U87 as well as increased apoptosis of these cells. The pathways related to tumorigenicity and tumor progression, STAT2 and AdipoR1/AMPK/SIRT1 could be restrained by miR-3908. In conclusion, restoration of miR-3908 expression induced suppression of cancer progression and glioblastoma tumorigenicity. The present study discovered novel tumorigenesis associated with miR-3908, which may represent a new target in treatment for glioblastoma.

BACKGROUND: The mechanisms of lipid raft regulation by microRNAs in breast cancer are not fully understood. This work focused on the evaluation and identification of miR-3908, which may be a potential biomarker related to the migration of breast cancer cells, and elucidates lipid-raft-regulating cell migration in breast cancer.
METHODS: To confirm the prediction that miR-3908 is matched with AdipoR1, we used 3'-UTR luciferase activity of AdipoR1 to assess this. Then, human breast cancer cell line MCF-7 was cultured in the absence or presence of the mimics or inhibitors of miR-3908, after which the biological functions of MCF-7 cells were analyzed. The protein expression of AdipoR1, AMPK, and SIRT-1 were examined. The interaction between AdipoR1 and Flotillin-1, or its effects on lipid rafts on regulating cell migration of MCF-7, was also investigated.
RESULTS: AdipoR1 is a direct target of miR-3908. miR-3908 suppresses the expression of AdipoR1 and its downstream pathway genes, including AMPK, p-AMPK, and SIRT-1. miR-3908 enhances the process of breast cancer cell clonogenicity. miR-3908 exerts its effects on the proliferation and migration of MCF-7 cells, which are mediated by lipid rafts regulating AdipoR1's ability to bind Flotillin-1.
CONCLUSIONS: miR-3908 is a crucial mediator of the migration process in breast cancer cells. Lipid rafts regulate the interactions between AdipoR1 and Flotillin-1 and then the migration process associated with miR-3908 in MCF-7 cells. Our findings suggest that targeting miR-3908 and the lipid raft, may be a promising strategy for the treatment and prevention of breast cancer.

BACKGROUND: Postdiagnosis weight gain in patients with breast cancer has been associated with increased cancer recurrence and mortality. This study was designed to identify risk factors for weight gain and create a predictive model to identify a high-risk population for targeted interventions.
METHODS: The weight of 393 patients with breast cancer from the Northwestern Robert H. Lurie Cancer Center was measured over a 2-year period from diagnosis, with body mass index (BMI) change over 18 months as the primary endpoint. Demographics, clinical factors, treatment methods, as well as tumor characteristics were also recorded; and a lifestyle questionnaire was conducted. Blood samples were genotyped for 16 single nucleotide polymorphisms in FTO, adiponectin pathway genes (ADIPOQ, ADIPOR1), and FNDC5. Serum leptin, adiponectin, and irisin levels also were measured.
RESULTS: Mean ± standard deviation 18-month BMI changes were 0.68 ± 1.42, 0.98 ± 1.62, 0.79 ± 1.74, and -0.44 ± 1.58 kg/m
CONCLUSIONS: Women age 60 years and younger at the time of breast cancer diagnosis who have an obesity genetic risk model are at increased risk for weight gain after treatment and should be targeted for weight-maintenance interventions. Cancer 2017;123:2413-21. © 2017 American Cancer Society.

BACKGROUND: Adipose microenvironment is involved in signaling pathways that influence breast cancer. We aim to characterize factors that are modified: 1) in tumor and non tumor human breast epithelial cell lines when incubated with conditioned media (CMs) from human breast cancer adipose tissue explants (hATT) or normal breast adipose tissue explants (hATN); 2) in hATN-CMs vs hATT-CMs; 3) in the tumor associated adipocytes vs. non tumor associated adipocytes.
METHODS: We used hATN or hATT- CMs on tumor and non-tumor breast cancer cell lines. We evaluated changes in versican, CD44, ADAMTS1 and Adipo R1 expression on cell lines or in the different CMs. In addition we evaluated changes in the morphology and expression of these factors in slices of the different adipose tissues. The statistical significance between different experimental conditions was evaluated by one-way ANOVA. Tukey's post-hoc tests were performed within each individual treatment.
RESULTS: hATT-CMs increase versican, CD44, ADAMTS1 and Adipo R1 expression in breast cancer epithelial cells. Furthermore, hATT-CMs present higher levels of versican expression compared to hATN-CMs. In addition, we observed a loss of effect in cellular migration when we pre-incubated hATT-CMs with chondroitinase ABC, which cleaves GAGs chains bound to the versican core protein, thus losing the ability to bind to CD44. Adipocytes associated with the invasive front are reduced in size compared to adipocytes that are farther away. Also, hATT adipocytes express significantly higher amounts of versican, CD44 and Adipo R1, and significantly lower amounts of adiponectin and perilipin, unlike hATN adipocytes.
CONCLUSIONS: We conclude that hATT secrete a different set of proteins compared to hATN. Furthermore, versican, a proteoglycan that is overexpressed in hATT-CMs compared to hATN-CMs, might be involved in the tumorogenic behavior observed in both cell lines employed. In addition, we may conclude that adipocytes from the tumor microenvironment show a less differentiated state than adipocytes from normal microenvironment. This would indicate a loss of normal functions in mature adipocytes (such as energy storage), in support of others that might favor tumor growth.

PURPOSE: To assess IGFBP-6 expression in relation with the presence of the metabolic syndrome, adiponectin receptors (AdipoR1 and AdipoR2) and IGF-IR levels in colorectal adenocarcinoma cases.
MATERIALS AND METHODS: IGFBP-6 mRNA and protein levels were analyzed using real-time quantitative PCR and Western blotting in 46 patients. ELISA and ow cytometry were used for evaluation of AdipoR1, AdipoR2 and IGF-IR.
RESULTS: The results showed that IGFBP-6 mRNA expression and the IGFBP-6 content were higher in tumor tissue samples of colorectal cancer patients with and without the metabolic syndrome. In addition, IGFBP-6 mRNA expression was associated with tumor invasion (tumor size) and the IGFBP-6 protein level was associated with nodal status. Positive correlations and positive nonlinear relations were found between the IGFBP-6 level and the AdipoR1 and AdipoR2 contents in colorectal cancer patients.
CONCLUSIONS: The IGFBP-6 mRNA level and protein level were found to be associated with presence of the metabolic syndrome. Positive correlations indicated probable cross-talk between the IGF-IR-mediated and adiponectin-mediated signaling pathways in colorectal carcinomas. IGFBP-6 may be considered as a potential biomarker associated with lymphogenous metastasis and the metabolic syndrome in colorectal cancer.

PURPOSE: To investigate the expression of Adaptor protein containing a PH domain, PTB domain and leucine zipper motif 1 (APPL1), insulin receptor (INSR), adiponectin and adiponectin receptors (adipoR1 and R2) and their possible associations in granulosa cells (GCs) of 22 polycystic ovary syndrome (PCOS) women compared to the 22 non-PCOS controls with normal ovulatory function matched for BMI (body mass index).
METHODS: In this study, 44 infertile women aged 18-40 years undergoing in vitro fertilization (IVF) protocol were recruited. After follicular fluid collection, GCs were isolated and then purified with MACS (Micro Beads conjugated to monoclonal anti-human CD45 antibodies). RNA was extracted from GCs and quantitative real-time PCR (qRT-PCR) was performed to assess APPL1 gene expression.
RESULTS: Expression of APPL1, insulin receptor and adiponectin system genes was significantly decreased in PCOS group compared to the controls.
CONCLUSIONS: Reduction of APPL1, insulin receptor and adiponectin system genes in GCs could be involved in the development of PCOS.

PURPOSE: The purpose of the study was to investigate changes in adiponectin system expression in granulosa cells (GCs) and high molecular weight adiponectin levels in serum and follicular fluid (FF) of 40 women with polycystic ovary syndrome (PCOS) compared to those in 40 women with normal ovary function.
METHODS: Adiponectin (Adipo), adiponectin receptor 1 (AdipoR1), and adiponectin receptor 2 (AdipoR2) messenger RNA (mRNA) expression levels were measured using quantitative real-time polymerase chain reaction (qRT-PCR). High molecular weight (HMW) adiponectin protein concentration was evaluated by ELISA method. Data were analyzed using Student's t test and one-way ANOVA in SPSS 21 software. At oocyte retrieval, FF was aspirated and GCs were obtained from a pooled collection of FF per each patient.
RESULTS: PCR results showed expression of adiponectin, AdipoR1, AdipoR2, follicle-stimulating hormone receptor (FSHR), and luteinizing hormone receptor (LHR) in GCs. After controlling body mass index (BMI) values, qRT-PCR demonstrated a decreased expression of adiponectin system in GCs of PCOS patients compared to those in controls (p = 0.001). There was a strong positive correlation among AdipoR1 and AdipoR2 expression and also among FSH and LH receptor expression. (Both r = 0.8, p = 0.001). There were low levels of high molecular weight adiponectin in the serum of PCOS patients with controlled ovarian hyperstimulation (30.19 ± 4.3 ng/ml) compared to the controls (48.47 ± 5.9 ng/ml) and in the FF of PCOS patients with controlled ovarian hyperstimulation (7.86 ± 1.44 ng/ml) compared to the controls (14.22 ± 2.01 ng/ml; p = 0.02).
CONCLUSIONS: Lower expression of adiponectin and its receptors in GCs might be an important manifestation in gonadotropin-stimulated PCOS patients which could influence the physiologic adiponectin roles such as interaction with insulin and LH in induction of GC gene expression.

Hyperandrogenemia, hyperinsulinemia, and obesity affect 60-70% of patients with Polycystic Ovarian Syndrome (PCOS), who exhibit an altered endometrial insulin signaling. The aim of the study was to evaluate whether hyperandrogenism, hyperinsulinism, and obesity present in PCOS patients impair the endometrial adiponectin signaling pathway. The ex vivo study was conducted on 27 samples from lean (n=9), obese (n=9), and obese-PCOS (n=9) patients. The in vitro assays were performed in immortalized human endometrial stromal cells stimulated with testosterone, insulin, or testosterone plus insulin. Serum steroid-hormones, adiponectin, glucose, and insulin; body mass index, free androgen index, ISI-Composite, and HOMA were evaluated in the 3 groups. Ex vivo and in vitro gene expression and protein content of adiponectin, AdipoR1, AdipoR2, and APPL1 were determined. Adiponectin serum levels were decreased in obese-PCOS patients compared to lean (78%) and obese (54%) controls (p<0.05). AdipoR1 protein and gene expression were increased in obese group vs. obese-PCOS and lean groups (2-fold, p<0.05). In turn, AdipoR2 protein and mRNA content was similar between the 3 groups. APPL1 protein levels were reduced in endometria from both obese groups, compared to lean group (6-fold, p<0.05). Testosterone plus insulin stimulation of T-HESC and St-T1b leads to a reduction of adiponectin, AdipoR1, AdipoR2, and APPL1 protein content in both endometrial cell lines (p<0.05), whereas, in the presence of testosterone or insulin alone, protein levels were similar to basal. Therefore, endometrial adiponectin-signaling pathway is impaired in hyperandrogenemic and hyperinsulinemic obese-PCOS patients, corroborated in the in vitro model, which could affect endometrial function and potentially the implantation process.

BACKGROUND/AIMS: The current treatments fail to provide satisfactory cure for aggressive prostate cancers (PCs). Hence, further comprehension of PC metastasis is highly appreciated for improving the levels of therapy. We have previously shown that Adiponectin reduces the levels of vascular endothelial growth factor A (VEGF-A) in PCs to suppress tumor-associated neovascularization, possibly through AMPK/mTor signaling. Here, we studied the regulation of Adiponectin signaling in PCs.
METHODS: We analyzed the levels and correlation of Adiponectin receptor 1 (AdipoR1) and microRNA-323 (miR-323) in the PC specimen, compared to the paired normal prostate tissue. We analyzed the binding of miR-323 to the 3'UTR of AdipoR1 mRNA and its effects on AdipoR1 translation by bioinformatics analysis and by luciferase-reporter assay, respectively. We modified miR-323 levels in PC cells, and examined the effects on the expression of AdipoR1 and VEGF-A, as well as on vessel formation in a human umbilical vein endothelial cells (HUVECs) transwell collagen gel assay.
RESULTS: We detected significantly lower levels of AdipoR1 and significantly higher levels of miR-323 in PC specimen. Moreover, the levels of AdipoR1 and miR-323 are inversely correlated. Moreover, miR-323 was found to bind to the 3’UTR of AdipoR1 mRNA to inhibit its translation. Overexpression of miR-323 in PC cells decreased AdipoR1 protein levels, whereas inhibition of miR-323 increased AdipoR1 protein levels, without affecting AdipoR1 transcripts. Moreover, overexpression of miR-323 increased the levels of VEGF-A and the vessel formation by HUVECs, while inhibition of miR- 323 decreased the levels of VEGF-A and the vessel formation by HUVECs.
CONCLUSION: Our data demonstrate that miR-323 may increase VEGF-A-mediated cancer vascularization in PC cells through AdipoR1 suppression.

BACKGROUND: Studies have come to conflicting conclusions about whether polymorphisms in the adiponectin receptor 1 gene (ADIPOR1) are associated with cancer risk. To help resolve this question, we meta-analyzed case-control studies in the literature.
METHODS: PubMed, EMBASE, Cochrane Library, the Chinese Biological Medical Database and the Chinese National Knowledge Infrastructure Database were systematically searched to identify all case-control studies published through February 2015 examining any ADIPOR1 polymorphisms and risk of any type of cancer. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated.
RESULTS: A total of 13 case-control studies involving 5,750 cases and 6,762 controls were analyzed. Analysis of the entire study population revealed a significant association between rs1342387(G/A) and overall cancer risk using a homozygous model (OR 0.82, 95%CI 0.72 to 0.94), heterozygous model (OR 0.84, 95%CI 0.76 to 0.93), dominant model (OR 0.85, 95%CI 0.75 to 0.97) and allele contrast model (OR 0.88, 95%CI 0.80 to 0.97). However, subgroup analysis showed that this association was significant only for Asians in the case of colorectal cancer. No significant associations were found between rs12733285(C/T) or rs7539542(C/G) and cancer risk, either in analyses of the entire study population or in analyses of subgroups.
CONCLUSIONS: Our meta-analysis suggests that the ADIPOR1 rs1342387(G/A) polymorphism, but not rs12733285(C/T) or rs7539542(C/G), may be associated with cancer risk, especially risk of colorectal cancer in Asians. Large, well-designed studies are needed to verify our findings.

OBJECTIVES: Recent evidence suggests that higher body mass index is associated with a modest increase in ovarian cancer risk. Reduced serum levels of adiponectin are correlated with obesity and increased cancer risk. The objectives of the present study are to determine if expressions of adiponectin and its receptors, AdipoR1 and AdipoR2, are altered in epithelial ovarian tumors and ascites-derived ovarian cancer cell lines and to determine if plasma adiponectin levels are altered in the chicken model of ovarian cancer.
METHODS: Adiponectin, AdipoR1, and AdipoR2 mRNA concentrations in ovaries and chicken ovarian cancer (COVCAR) cell lines were determined by quantitative real-time polymerase chain reaction analysis. Existence of adiponectin isoforms in the ovaries and COVCAR cells was identified by nondenaturing gel electrophoresis. Adiponectin, AdipoR1, and AdipoR2 protein amounts were determined by Western blot analysis. Plasma total adiponectin levels were determined by an enzyme immunoassay.
RESULTS: Adiponectin, AdipoR1, and AdipoR2 mRNA concentrations were significantly lower in cancerous ovaries and COVCAR cell lines compared with normal ovaries and normal ovarian surface epithelial (NOSE) cells, respectively. Adiponectin in ovary and COVCAR cell lines appeared as a heavy-molecular-weight isoform that is greater than 720-kd mass. In addition, a lower-molecular-weight adiponectin isoform was found in COVCAR cells but not in NOSE cells. Adiponectin and AdipoR1 protein concentrations were not different in COVCAR cell lines compared with NOSE cells. However, AdipoR2 protein concentrations were significantly higher in cancerous ovaries but lower in COVCAR cell lines compared with normal ovaries and NOSE cells, respectively. Plasma adiponectin concentrations were not different in chickens that had ovarian carcinoma compared with control animals.
CONCLUSIONS: Expression of adiponectin in ovarian tumors and in metastatic ovarian tumor cells is likely to affect cellular metabolism and proliferation through activating AdipoR1 and/or AdipoR2. Plasma adiponectin levels may not be predictive of advanced stages of ovarian tumor in the chicken model.

BACKGROUND: Human adiponectin (ApN), a 30 kDa glycoprotein of 244-amino acids which is predominantly produced by adipocytes, exerts its effects via two receptors, namely adiponectin receptor-1 (adipo-R1) and adiponectin receptor-2 (adipo-R2) with differential binding affinity to globular adiponectin. Adiponectin receptor expression has been studied in several cancer tissues. However, there are no studies of colorectal adenomas which are considered to be precursors for colorectal carcinoma (CRC).
OBJECTIVES: In the present study, the expression of adipo-R1 and adipo-R2 was investigated immunohistochemically in colorectal adenomas and colorectal carcinoma tissues in an attempt to determine associations with these tumors.
MATERIALS AND METHODS: The study enrolled 50 CRC patients with tumor resection and 82 patients who were diagnosed with adenomatous polyps, classified as negative for neoplasia, low-grade dysplasia (L-GD) or high- grade dysplasia (H-GD).
RESULTS: Expression of both adipo-R1 and adipo-R2 was found to be significantly lower in the CRCs than in colorectal adenomas (tubular and tubulovillous, p=0.009 and p<0.001, respectively). Adipo-R1 and adipo-R2 expression was also significantly lower in the CRC group when compared with the groups of patients with low grade dysplasia, high-grade dysplasia or no neoplasia (p=0.012 and p<0.001, respectively). In addition, it was observed that adipo-R2 expression was generally positive in the non-neoplastic group irrespective of the adipo-R2 expression. In the L-GD, H-GD and CRC groups, the adipo-R2 result was positive whenever adipo-R1 result was positive but some patients with negative adipo-R1 had positive adipo-R2 (p<0.001, p=0.004, p<0.001, respectively).
CONCLUSIONS: This study indicated that ApN may play a role in the progression of colorectal adenomatous polyps to carcinoma through actions on adipo-R1 and adipo-R2 receptors.

Adiponectin, a member of adipokines, is a functional ligand for Adiponectin Receptor-1 (AdipoR1) and Adiponectin Receptor-2 (AdipoR2), and has been found to be linked to the risk of CML. Imatinib has undoubtedly revolutionised the management and outcome of chronic myeloid leukemia (CML), however imatinib resistance has been recognized as a major problem in CML therapy. In this study, we first established imatinib-resistant K562 CML cells, and then evaluated the effect of Adiponectin in reversing imatinib resistance. The data presented here demonstrated that Adiponectin was able to reverse K562 resistance to imatinib in vitro and in vivo. Additional data with molecular approaches suggested that the reversion of Adiponectin in imatinib resistance signals through AdipoR1 but not AdipoR2 to downregulate Bcr-Abl expression and effect in imatinib-resistant K562 CML cells. Taken together, our data showed that Adiponectin can reverse imatinib resistance in CML, and to a certain extent elucidate the mechanism of Adiponectin reversing imatinib resistance that may provide a new and promising approach in imatinib resistance management in CML therapy.

Adiponectin is a protein hormone secreted exclusively by adipocytes and it is responsible for insulin sensitization in the human body. Deregulation of adiponectin and its downstream signaling pathway genes have been found to be involved in the gastric cancer carcinogenesis; however, whether the variants on adiponectin (ADIPOQ) and adiponectin receptor 1 (ADIPOR1) affect the prognosis of gastric cancer patients are still unknown. Here we have recruited 455 gastric cancer patients, who have received the gastrectomy treatment to evaluate the prognostic effects of variants on ADIPOQ (rs266729 and rs822395) and AdipoR1 (rs12733285 and rs1342387) for the gastric cancer patients. No significant association between the four variants and the overall survival of the gastric cancer patients was found. However, for those patients without a previous history of alcohol drinking, the rs266729 GG/CG genotype carriers showed a significantly decreased gastric cancer mortality compared to homogeneity CC patients (HR 0.74, 95 % CI 0.56-0.97; p = 0.032) after adjustment for variants age, sex, smoking status, tumor stage, tumor location and post-surgery chemotherapy. No significant association between the variant rs266729 genotypes and overall survival for the gastric cancer patients with an alcohol drinking habit. These data suggested that the variant rs266729 was an independent prognostic factor for the never drinking gastric cancer patients who received surgical treatment.

Adiponectin is an adipocyte-secreted adipokine with pleiotropic actions. Clinical evidence has shown that serum adiponectin levels are increased and that adiponectin can protect pancreatic beta cells against apoptosis, which suggests that adiponectin may play an anti-apoptotic role in pancreatic cancer (PC). Here, we investigated the effects of adiponectin on PC development and elucidated the underlying molecular mechanisms. Adiponectin deficiency markedly attenuated pancreatic tumorigenesis in vivo. We found that adiponectin significantly inhibited the apoptosis of both human and mouse pancreatic cancer cells via adipoR1, but not adipoR2. Furthermore, adiponectin can increase AMP-activated protein kinase (AMPK) phosphorylation and NAD-dependent deacetylase sirtuin-1 (Sirt1) of PC cells. Knockdown of AMPK or Sirt1 can increase the apoptosis in PC cells. AMPK up-regulated Sirt1, and Sirt1 can inversely phosphorylate AMPK. Further studies have shown that Sirt1 can deacetylate peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α), which can increase the expression levels of mitochondrial genes. Thus, adiponectin exerts potent anti-apoptotic effects on PC cells via the activation of AMPK/Sirt1/PGC1α signaling. Finally, adiponectin can elevate β-catenin levels. Taken together, these novel findings reveal an unconventional role of adiponectin in promoting pancreatic cancers, and suggest that the effects of adiponectin on tumorigenesis are highly tissue-dependent.

INTRODUCTION: Adiponectin (ApN) is a complement C1q-related protein, mainly secreted from adipose tissue, that signals through ApN receptor 1 (Adipo-R1) and ApN receptor 2 (Adipo-R2). Low serum ApN concentrations are associated with obesity-related malignancies. However, there are very few studies on any prognostic role of ApN receptors in gastric cancer.
OBJECTIVES: The aim of this study is to investigate the relationship between AdipoR1/R2 expression and early/advanced stage gastric cancer in terms of clinicopathologic characteristics and survival.
MATERIALS AND METHODS: Eighteen patients with early and 39 with advanced stage gastric cancer who underwent surgical gastric resection were included in this study.
RESULTS: Adipo-R1 expression was low in 2 of the 18 patients with early stage gastric cancer (11.1%), while 4 had low Adipo-R2 expression (22.2%). In those with advanced stage gastric cancer, 7 of 39 had low Adipo-R1 expression (17.9%) and 16 had low Adipo-R2 expression (41%). Adipo-R2 expression was significantly higher (p=0.011) in moderately differentiated tumors when compared to well-differentiated tumors. While there was nearly a statistically significant relationship between TNM stage (T, tumor size; N, regional lymph node; M, whether distant metastases exist) and Adipo-R2 expression (p=0.054), there was no relationship between Adipo-R1/-R2 expression with tumor stage and survival.
CONCLUSION: Adipo-R1/-R2 expression has no prognostic significance of in early/advanced stage gastric cancer.

OBJECTIVE: Low plasma adiponectin levels are linked to obesity, insulin resistance, and the risk of several types of malignancy. Despite the decline in circulating adiponectin concentrations, the increase in the expression of adiponectin receptors AdipoR1 and AdipoR2 is greater in cancerous than in normal colonic tissue. The purpose of this study was to obtain new information regarding local adiponectin signaling in the pathogenesis of colorectal cancer (CRC).
METHODS: We characterized the expressions of adiponectin and several of its downstream targets in paired samples of tumor tissue and adjacent noncancerous mucosa in 60 surgical patients with colorectal adenocarcinomas.
RESULTS: Adiponectin was expressed in both colorectal tumors and the adjacent mucosa. The expressions of adiponectin mRNA and its globular protein variant (gAd), adiponectin receptor type 1 and 5' AMP-activated protein kinase (AMPK) mRNA were significantly higher in colorectal tumors than in the adjacent mucosa. This finding was accompanied by increased mRNA expression of genes encoding proteins involved in fatty-acid trafficking and oxidation. The potential interference between adiponectin stimulation and AMPK activation through AMPK1 was examined in an in vitro model with the aid of silencing-RNA experiments. Furthermore, AMPK mRNA expression on tumors was positively correlated with a more advanced tumor stage in the patients.
CONCLUSION: We propose that the globular adiponectin-AMPK pathway functions in an autocrine manner in colorectal tumors, explaining some of the beneficial changes in cellular oxidative capacity in tumors in favor of tumorigenesis.

Adiponectin, the most abundant protein secreted by adipose tissue, exhibits insulin-sensitizing, anti-inflammatory, antiatherogenic, and antiproliferative properties. In addition, it appears to play an important role also in the development and progression of several obesity-related malignancies, including breast cancer.   Here, we demonstrated that adiponectin induces a dichotomic effect on breast cancer growth. Indeed, it stimulates growth in ERα+ MCF-7 cells while inhibiting proliferation of ERα- MDA-MB-231 cells. Notably, only in MCF-7 cells adiponectin exposure exerts a rapid activation of MAPK phosphorylation, which is markedly reduced when knockdown of the ERα gene occurred. In addition, adiponectin induces rapid IGF-IR phosphorylation in MCF-7 cells, and the use of ERα siRNA prevents this effect. Moreover, MAPK activation induced by adiponectin was reversed by IGF-IR siRNA. Coimmunoprecipitation studies show the existence of a multiprotein complex involving AdipoR1, APPL1, ERα, IGF-IR, and c-Src that is responsible for MAPK signaling activation in ERα+ positive breast cancer cells. It is well known that in addition to the rapid effects through non-genomic mechanisms, ERα also mediates nuclear genomic actions. In this concern, we demonstrated that adiponectin is able to transactivate ERα in MCF-7 cells. We showed the classical features of ERα transactivation: nuclear localization, downregulation of mRNA and protein levels, and upregulation of estrogen-dependent genes. Thus, our study clarifies the molecular mechanism through which adiponectin modulates breast cancer cell growth, providing evidences on the cell-type dependency of adiponectin action in relationship to ERα status.

BACKGROUND/AIMS: Adiponectin receptor 1 (ADIPOR1) is an identified receptor for adiponectin, an adipocytokine with anti-inflammatory and insulin-sensitizing properties. The ADIPOR1 gene is a potential candidate gene in polycystic ovary syndrome (PCOS). The aim of this study is to assess the association between single-nucleotide polymorphism (SNP) rs1539355 in the ADIPOR1 gene and PCOS in Chinese women.
METHODS: 302 patients with PCOS and 312 healthy controls were included in this study. The ADIPOR1 genotype distribution was detected using the polymerase chain reaction melting temperature shift method.
RESULTS: The genotypic distributions of SNP rs1539355 did not differ in patients with PCOS compared to controls. However, the frequency of the G allele in the PCOS group was significantly higher than that in the control group (p = 0.037). Patients with the AG or GG genotype had a higher homeostasis model assessment for insulin resistance (HOMA-IR) (p < 0.05) compared to patients with the AA genotype. The fasting insulin levels in subjects with the GG genotype were significantly higher than those in patients with the AA genotype (p < 0.05).
CONCLUSION: SNP rs1539355 in the ADIPOR1 gene is associated with insulin resistance in Chinese PCOS patients.

Polycystic ovary syndrome (PCOS), characterized by ovarian androgen excess, is the commonest endocrine disorder in women. Obesity increases androgen synthesis, a phenomenon attributed to the accompanying hyperinsulinemia. Our hypothesis was that adipokines, fat cell-derived hormones, play a direct role in modulating ovarian androgen secretion. Therefore, the aims of this study were to explore the effects of adipokines (in particular, adiponectin) on ovarian steroidogenesis and compare the expression of adiponectin receptors in ovaries from women with and without PCO. Sections of archived human ovaries (nine from women with normal ovaries and 16 with PCOS, classified histologically, with reference to menstrual history and ultrasound) were analysed by quantitative morphometry and the proportion of positive-labelling cells compared. In addition, studies of androgen production in relation to adipokine function in primary bovine theca cell culture were also performed. A significantly lower proportion of theca cells expressed adiponectin receptors 1 and 2 (AdipoR1, AdipoR2) in polycystic ovaries than in normal ovaries. In cultured theca cells, adiponectin suppressed androstenedione production and gene expression of LH receptor and key enzymes in the androgen synthesis pathway. Moreover, knockdown of genes for AdipoR1 and AdipoR2 was associated with increased androstenedione secretion by bovine theca cells. These results provide evidence for a direct link between fat cell metabolism and ovarian steroidogenesis, suggesting that disruption of adiponectin and/or its receptors plays a key role in pathogenesis of hyperandrogenism in PCOS.

BACKGROUND: Post-diagnosis weight gain in breast cancer patients has been associated with increased cancer recurrence and mortality. Our study was designed to identify risk factors for this weight gain and create a predictive model to identify a high-risk population for targeted interventions.
METHODS: Chart review was conducted on 459 breast cancer patients from Northwestern Robert H. Lurie Cancer Centre to obtain weights and body mass indices (BMIs) over an 18-month period from diagnosis. We also recorded tumour characteristics, demographics, clinical factors, and treatment regimens. Blood samples were genotyped for 14 single-nucleotide polymorphisms (SNPs) in fat mass and obesity-associated protein (FTO) and adiponectin pathway genes (ADIPOQ and ADIPOR1).
RESULTS: In all, 56% of patients had >0.5 kg m(-2) increase in BMI from diagnosis to 18 months, with average BMI and weight gain of 1.9 kg m(-2) and 5.1 kg, respectively. Our best predictive model was a primarily SNP-based model incorporating all 14 FTO and adiponectin pathway SNPs studied, their epistatic interactions, and age and BMI at diagnosis, with area under receiver operating characteristic curve of 0.85 for 18-month weight gain.
CONCLUSION: We created a powerful risk prediction model that can identify breast cancer patients at high risk for weight gain.