Androgen Receptors In Hepatocellular Carcinoma Research Articles

Constitutively Active Androgen Receptor in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the predominant type of liver cancer and a leading cause of cancer-related death globally. It is also a sexually dimorphic disease with a male predominance both in HCC and in its precursors, non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH). The role of the androgen receptor (AR) in HCC has been well documented; however, AR-targeted therapies have failed to demonstrate efficacy in HCC. Building upon understandings of AR in prostate cancer (PCa), this review examines the role of AR in HCC, non-androgen-mediated mechanisms of induced AR expression, the existence of AR splice variants (AR-SV) in HCC and concludes by surveying current AR-targeted therapeutic approaches in PCa that show potential for efficacy in HCC in light of AR-SV expression.

Phosphorylation of androgen receptor by mTORC1 promotes liver steatosis and tumorigenesis.

Background and AimsAndrogen receptor (AR) has been reported to play an important role in the development and progression of man’s prostate cancer. Hepatocellular carcinoma (HCC) is also male‐dominant, but the role of AR in HCC remains poorly understood. Mechanistic target of rapamycin complex 1 (mTORC1) also has been reported to be highly activated in HCC. In this study, we aimed to explore the role of AR phosphorylation and its relationship with mTORC1 in hepatocarcinogenesis.Approach and ResultsIn vitro experiment, we observed that mTORC1 interacts with hepatic AR and phosphorylates it at S96 in response to nutrient and mitogenic stimuli in HCC cells. S96 phosphorylation promotes the stability, nuclear localization, and transcriptional activity of AR, which enhances de novo lipogenesis and proliferation in hepatocytes and induces liver steatosis and hepatocarcinogenesis in mice independently and cooperatively with androgen. Furthermore, high ARS96 phosphorylation is observed in human liver steatotic and HCC tissues and is associated with overall survival and disease‐free survival, which has been proven as an independent survival predictor for patients with HCC.ConclusionsAR S96 phosphorylation by mTORC1 drives liver steatosis and HCC development and progression independently and cooperatively with androgen, which not only explains why HCC is man‐biased but also provides a target molecule for prevention and treatment of HCC and a potential survival predictor in patients with HCC.

Androgen receptor affects the response to immune checkpoint therapy by suppressing PD-L1 in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a heterogeneous malignancy with gender-related differences in onset and course. Androgen receptor (AR), a male hormone receptor, is critical in the initiation and progression of HCC. The role of AR in HCC has been mechanistically characterized and anti-AR therapies have been developed, showing limited efficacy. Immunotherapy targeting immune checkpoint proteins may substantially improve the clinical management of HCC. The mechanism by which AR influences HCC immune state remains unclear. In this study, we demonstrated that AR negatively regulated PD-L1, by acting as a transcriptional repressor of PD-L1. Notably, AR over-expression in HCC cells enhanced CD8+T function in vitro. We then verified the AR/PD-L1 correlation in patients. In animal experiment we found that lower AR expressed tumor achieved better response to PD-L1 inhibitor. Thus, AR suppressed PD-L1 expression, possibly contributing to gender disparity in HCC. Better understanding of the roles of AR during HCC initiation and progression will provide a novel angle to develop potential HCC immunotherapies.

Androgen Receptor Enhances the Efficacy of Sorafenib Against Hepatocellular Carcinoma Through Enriched EpCAM Stemness.

The role of androgen receptor (AR) in hepatocellular carcinoma (HCC) development is controversial. Therefore, the translational value of targeting AR in HCC is unknown. Sorafenib, a multiple kinase inhibitor, is the standard therapy for patients with unresectable HCC. This study investigated sorafenib effect on AR in experimental models of HCC. AR cDNA was introduced into HCC cells and in vitro cell growth and in vivo tumor growth were measured. Sphere cells, as well as epithelial cell adhesion molecule-positive (EpCAM+) and CD133+ cells were isolated from HCC cells with/without AR expression to observe in vitro/in vivo effects. Liver specific AR knockout in mouse models of spontaneous HCC (carcinogen-induced and hepatitis B virus-related HCC) was also implemented to examine gene expression. HCC cells/tumors were treated with sorafenib in order to determine effects on tumor growth and related gene expression. AR cDNA increased transactivation function, increased colony/sphere-forming activities, and enhanced tumorigenicity in HCC cells compared to their parental cells. Expression of the stemness marker EpCAM was also dramatically increased. In carcinogen-and HBV-induced HCC models, EpCAM+ cells were significantly reduced in AR-knockout mice compared to wild-type HCCs. In addition, AR reduced sorafenib-related signals, e.g. extracellular-regulated kinase, AKT serine/threonine kinase 1, and p38 mitogen-activated protein kinase, compared to that in parental cells. Regarding sorafenib cytotoxicity, AR-expressing cells were vulnerable to treatment. Moreover, the half maximal-inhibitory concentration (IC50) was drastically lowered in AR+/EpCAM+ compared to AR-/EpCAM- sphere cells. Strikingly, the IC50 in AR+/CD133+ vs. AR-/CD133+ cells were similar. Moreover, sorafenib robustly suppressed tumor growth in implanted AR+/EpCAM+ cells but not AR-/EpCAM- ones. Finally, bioinformatics analyses revealed EpCAM to be a prognostic biomarker in Asian and non-alcohol-consuming patients with HCC, suggesting suitability of a sorafenib regimen for such patients. AR+/EpCAM+ may be a marker of responsiveness to sorafenib for patients with HCC. Prospective surveys associating AR/EpCAM expression with therapy outcomes are essential.

Circular RNA expression is suppressed by androgen receptor (AR)-regulated adenosine deaminase that acts on RNA (ADAR1) in human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a heterogeneous malignancy as a result of complex genetic and epigenetic alterations. HCC is characterized by a clear gender disparity for which there is lack of a clear mechanistic understanding. Androgen receptor (AR) is thought to be critical for such bias. Meanwhile, the potential function of circular RNA (circRNA), regulated by RNA editing enzyme, remained largely unknown in malignancy till now. By utilizing circRNA microarray survey coupled with in vitro analysis, we analyzed the influence of AR on circRNA expression in HCC. Our results indicated that AR could suppress circRNA expression by upregulating ADAR1 p110. Such effect is because AR served as a transcriptional activator of ADAR1 promoter. More significantly, data collected from our center strongly suggest that ADAR1 expression can effectively predict HCC patients’ prognosis and an abnormal overexpression of ADAR1 is positively correlated with AR in HCC. In addition, we found CircARSP91 (hsa_circ_0085154), one of the circRNAs downregulated by AR in an ADAR1-dependent manner, could inhibit HCC tumor growth both in vitro and in vivo. These findings highlight the fact that AR as a contributing factor for gender disparity in HCC can cause complex consequences though regulation of circRNA expression. Better understanding of the roles of circRNA during HCC initiation and progression will provide a novel angle to develop potential HCC therapies.

Acetylcholine Acts on Androgen Receptor to Promote the Migration and Invasion but Inhibit the Apoptosis of Human Hepatocarcinoma

Hepatocellular carcinoma (HCC) is one of the most fatal cancers. In almost all populations, males have a higher HCC rate than females. Here we sought to explore the roles and mechanisms of acetylcholine (Ach) and androgen receptor (AR) on regulating the fate determinations of HCC. Ach activated AR and promoted its expression in HCC cells. Ach enhanced HCC cell migration and invasion but inhibited their apoptosis. Ach had no obvious effects on the migration, invasion, or apoptosis in AR-negative HCC cells. Elevation of migration and invasion induced by Ach was eliminated in AR-knockdown HCC cells. In contrast, Ach stimulated the migration and invasion but suppressed apoptosis in AR over-expressed HCC cells. Additionally, AR agonist R1881 promoted the migration and invasion but reduced the apoptosis of SNU-449 cells, whereas AR antagonist casodex inhibited the migration and invasion but stimulated the apoptosis of SNU-449 cells. STAT3 and AKT phosphorylation was activated by Ach in HCC cells. Collectively, these data suggest that Ach activates STAT3 and AKT pathways and acts on AR to promote the migration and invasion but inhibit the apoptosis of HCC cells. This study thus provides novel insights into carcinogenesis of liver cancer by local interaction between neurotransmitter Ach and hormone receptor AR in HCC.

Protective Role of Estrogen-induced miRNA-29 Expression in Carbon Tetrachloride-induced Mouse Liver Injury

Previous studies have indicated that female animals are more resistant to carbon tetrachloride (CCl(4))-induced liver fibrosis than male animals, and that estradiol (E(2)) treatment can inhibit CCl(4)-induced animal hepatic fibrosis. The underlying mechanism governing these phenomena, however, has not been fully elucidated. Here we reported the role of estrogen-induced miRNA-29 (miR-29) expression in CCl(4)-induced mouse liver injury. Hepatic miR-29 levels were differentially regulated in female and male mice during CCl(4) treatment. Specifically, the levels of miR-29a and miR-29b expression were significantly decreased in the livers of male, but not female, mice following 4 weeks of CCl(4) treatment. The down-regulation of miR-29a and miR-29b in male mouse livers correlated with the early development of liver fibrosis, as indicated by increased expressions of fibrotic markers in male mice relative to female mice. In addition, E(2) was maintained at a higher level in female mice than in male mice. In contrast to TGF-β1 that decreased miR-29a/b expression in murine hepatoma IAR20 cells and normal hepatocytes, E(2) enhanced the expression of miR-29a/b through suppression of the nuclear factor-κB (NF-κB) signal pathway, which negatively regulates miR-29 expression. Furthermore, both E(2) treatment and intravenous injection of the recombinant adenovirus expressing miR-29a/b markedly increased the miR-29a/b level and attenuated the expression of fibrotic markers in mouse livers during CCl(4) treatment, supporting the protective role of E(2)-induced miR-29 in CCl(4)-induced hepatic injury. In conclusion, our results collectively demonstrate that estrogen can inhibit CCl(4)-induced hepatic injury through the induction of hepatic miR-29.

Androgen receptors in hepatocellular carcinoma and surrounding liver: relationship with tumor size and recurrence rate after surgical resection

Background/Aims: This study aimed to evaluate the parameters associated with the presence of androgen receptors in hepatocellular carcinoma and surrounding non-tumoral liver. Furthermore, we have assessed whether androgen receptor positively influences disease recurrence after surgical resection. Methods: Androgen receptor concentration was calculated by receptor binding assay in tumoral and non-tumoral liver in 43 patients (40 of them with cirrhosis) with hepatocellular carcinoma who underwent surgical resection. Results: Androgen receptors were found in 28 of the tumoral and in 30 of the non-tumoral samples, at concentrations ranging between 5 and 211 fmol/mg protein. The presence of androgen receptors within the tumor was significantly related to a smaller tumor size. Thereby, 22 of the 29 nodules ≤3 cm contained androgen receptors, while this occurred in only six of the 14 tumors larger than 3 cm ( p<0.05). In contrast, the only parameter associated with the presence of androgen receptors in the non-tumoral liver was a lower gamma-glutamyltranspeptidase concentration. Disease recurrence after surgical resection was not only related to some tumor characteristics (increased alfa-fetoprotein concentration, presence of satellites, differentiation degree), but also to the presence of androgen receptors in the surrounding liver. Thus, the probability of recurrence after 1- and 2-year follow up in patients with androgen-positive livers was 33% and 50%, respectively, while it was 0% and 20% in those with androgen-negative livers ( p<0.05). In contrast, the presence of androgen receptors within the tumor was not associated with a higher recurrence rate. Conclusions: These results show that only two thirds of hepatocellular carcinomas contained androgen receptors and that this feature was more frequent in small tumors. In addition, our data indicate that the presence of androgen receptors within the tumor does not imply a different outcome after surgical resection. In contrast, the presence of these receptors in the surrounding non-tumoral liver may be considered a risk factor for a higher incidence of disease recurrence.

Quantitation of estrogen and androgen receptors in hepatocellular carcinoma and adjacent normal human liver.

Sex hormones have been shown to influence the development and course of several liver diseases. The worldwide predominance of hepatocellular carcinoma (HCC) in males has led to the suggestion that this disease might be hormone-responsive. Therefore, the hepatic estrogen (ER) and androgen receptor (AR) status of liver specimens from such patients was investigated. Samples were obtained from three female and six males patients undergoing liver resection; in each case, a small sample of both the tumor and adjacent normal tissue was collected. All patients had primary hepatocellular carcinoma without cirrhosis. In most cases, the tumor and the normal specimen had an equivalent content of cytosolic ER; however, three of the tumor samples (one female and two male) displayed considerably elevated cytosolic ER levels as compared to that of the normal tissue. In every sample, the tumor contained less nuclear ER than did the normal liver. When AR was measured, tumors of three patients (one female and two male) demonstrated a twofold elevation in cytosolic AR as compared to adjacent normal tissue. In the two male patients, an approximately twofold greater nuclear AR was found. Two other samples from male patients showed a modest elevation of cytosolic AR in the tumors. The patients whose tumors showed elevations in ER were not the same patients as those in whom the AR was elevated. Thus, these studies indicate that certain, but not all, specimens of HCC demonstrate either elevated ER or AR and suggest that a determination of receptor content might be useful prior to initiation of certain antihormone therapies.

Androgen Receptor in Hepatocellular Carcinoma as a Prognostic Factor After Hepatic Resection

Androgen receptors (AR) in the cytosol of hepatocellular carcinoma (HCC) were assayed in 45 unselected patients in whom radical hepatic resection was performed. Thirty-one patients had detectable amounts of ARs in tumors, ranging from 2.3 to 82.6 fmol/mg protein with the dissociation constants (Kd) of 4.1 - 30.9 x 10(-10) M. The receptor was not found in the remaining 14 cases. AR negative HCCs were significantly more common among women and nonalcoholic patients. Otherwise, there were no significant difference in the clinicopathologic background between patients with AR positive HCCs and those with AR negative tumors. Three patients died of liver failure in the former group, whereas two died in the latter; one patient died of liver failure and the other died of pneumonia (results were not statistically significant). Excluding those five operative deaths, the recurrence rates were 67.9% in the group of patients with AR positive HCCs and 33.3% in the group of patients with AR negative tumors (0.1 less than p less than 0.05). The 5-year survival rate was significantly better (p less than 0.05) in patients with AR negative HCCs (62.2%) than in those with the positive tumors (17.3%). In light of the current results and previous experimental works by others, it is likely that testosterones enhance the growth and invasiveness of human HCC, which is mediated by AR in the tumor.

Androgen receptor analysis on needle biopsy of the liver: A step closer in determining whether hepatocellular carcinomas are sex hormone-sensitive

The liver is a steroid-responsive organ and contains high levels of androgen receptors (AR). The present study investigated cytosolic AR concentrations in diseased human liver obtained by needle biopsy. Insufficient tissue was available for full Scatchard analysis. Previous studies have shown the binding affinity of the liver AR to be sufficiently constant to allow the use of a single saturating dose analysis, using 3H-mibolerone as the active ligand, for the estimation of binding sites. Thirteen samples were studied and compared to normal liver. AR was identified in all samples and the level negatively correlated to the degree of liver damage. A role for AR in hepatocellular carcinoma has been postulated and anti-androgens used in treatment. This study shows AR can be measured in needle-biopsy specimens and, if hepatocellular carcinoma is proven to be hormone sensitive, then this technique may help in the assessment of such tumours.

Androgen receptor concentrations in needle biopsy specimens of human liver.

The liver is a steroid-responsive organ and contains high levels of androgen receptors (AR). The present study investigated cytosolic AR concentrations in diseased human liver obtained by needle biopsy. Insufficient tissue was available for full Scatchard analysis. Previous studies have shown the binding affinity of the liver AR to be sufficiently constant to allow the use of a single saturating dose analysis, using 3H-mibolerone as the active ligand, for the estimation of binding sites. Thirteen samples were studied and compared to normal liver. AR was identified in all samples and the level negatively correlated to the degree of liver damage. A role for AR in hepatocellular carcinoma has been postulated and anti-androgens used in treatment. This study shows AR can be measured in needle-biopsy specimens and, if hepatocellular carcinoma is proven to be hormone sensitive, then this technique may help in the assessment of such tumours.

Androgen and estrogen receptors in hepatocellular carcinoma and in the surrounding noncancerous liver tissue.

Both androgen and estrogen receptors were studied in human hepatocellular carcinoma and noncancerous liver tissue surrounding it. Androgen receptor was detected in the cytosol and/or nucleosol of 4 of 8 cancerous tissues and 1 of 6 noncancerous tissues. The levels of androgen receptor in hepatocellular carcinomas ranged from 3.4 to 37.6 fmoles per mg protein with dissociation constants (Kd) of 0.226 - 51.3 X 10(-9) M. That in the surrounding noncancerous tissue was 2.1 fmoles per mg protein with Kd of 0.941 X 10(-9) M. Estrogen receptor was detected in the cytosol of 1 of 7 cancerous tissues, while it was detected in the cytosol and/or nucleosol of 3 of 7 noncancerous tissues. The level of estrogen receptor in hepatocellular carcinoma was 4.9 fmoles per mg protein with Kd of 1.20 X 10(-9) M, and those in the surrounding noncancerous tissues ranged from 2.6 to 1,073 fmoles per mg protein with Kd of 0.223 - 3.15 X 10(-9) M. The results suggest that the expression of androgen receptor may be augmented in association with malignant transformation of hepatocytes while the expression of estrogen receptor may be rather suppressed and that some of hepatocellular carcinomas may be androgen-dependent.

Characterisation of high affinity binding sites of androgens in primary hepatocellular carcinoma

The reported presence of androgen receptors (AR) in hepatocellular carcinoma (HCC) and foetal liver, but not in normal adult human liver, has been followed by further study of AR employing a new microassay. Tissues examined were: 5 samples of HCC with surrounding normal liver in 3 cases; 5 samples of cirrhotic liver and a single specimen of HCC in a child. High affinity binding of 5α-dihydrotestosterone (DHT) was detected in cytosol (11.5–21 fmol/mg, K d 1.5 × 10 −10−3.1 × 10 −11 mol/l) and in nucelosol (8.7–11.4 fmol/mg, 6.7−1.4 x 10 −11 mol/l) of the 5 HCC samples. All other liver samples exhibited non-specific binding only. Competition studies indicated that DHT, testosterone, androstenedione, 5α-androstan-3β, 17ß-diol, androst-5-ene-3β, 17β-diol and cyproterone acetate were acting at the same receptor binding site, relative displacement of 3H-DHT being 100, 85.7, 77.4, 67.8, 34.5 and 60.2 per cent respectively. Presence of 3.5S cytosolic and both 2.8S and 4S nucleosolic receptor patterns were demonstrated in both prostatic and HCC tissue. These studies confirm the presence of a cytosolic and nucleosolic androgen receptor in HCC which possesses similar characteristics to the AR of human prostate.

Androgen receptors in hepatocellular carcinoma and surrounding parenchyma

The androgen receptor content of normal human liver, hepatocellular carcinoma, and surrounding liver tissue was determined in patients with chronic liver disease. Androgen receptor was detected in all six normal livers obtained from 4 men and 2 women. The androgen receptor content in these 6 individuals ranged from 5.0 to 10.2 fmol/mg protein (Kd 10.6 − 31.8 × 10−10 M). The livers from 2 patients with chronic active hepatitis and from 10 cirrhotic patients with hepatocellular carcinoma had detectable amounts of androgen receptor ranging from 2.0 to 14.8 fmol/mg protein (Kd 4.0 − 30.9 × 10−10 M). Androgen receptor was found in the cytosol of 14 of 19 men with hepatocellular carcinoma. The titer ranged from 3.7 to 45.4 fmol/mg protein (Kd 3.2 − 21.4 × 10−10 M). Hepatocellular carcinoma had a significantly higher concentration of androgen receptor than did the surrounding cirrhotic liver tissue. In 2 men and 1 woman, androgen receptor was detected in the cirrhotic liver but not in the tumor. In the remaining 3 men, both tumor and cirrhotic liver were negative for androgen receptor.