Conformational Landscape of the p28-Bound Human Proteasome Regulatory Particle.

The proteasome holoenzyme is activated by its regulatory particle (RP) consisting of two subcomplexes, the lid and the base. A key event in base assembly is the formation of a heterohexameric ring of AAA-ATPases, which is guided by at least four RP assembly chaperones in mammals: PAAF1, p28/gankyrin, p27/PSMD9, and S5b. Using cryogenic electron microscopy, we analyzed the non-AAA structure of the p28-bound human RP at 4.5 Å resolution and determined seven distinct conformations of the Rpn1-p28-AAA subcomplex within the p28-bound RP at subnanometer resolutions. Remarkably, the p28-bound AAA ring does not form a channel in the free RP and spontaneously samples multiple "open" and "closed" topologies at the Rpt2-Rpt6 and Rpt3-Rpt4 interfaces. Our analysis suggests that p28 assists the proteolytic core particle to select a specific conformation of the ATPase ring for RP engagement and is released in a shoehorn-like fashion in the last step of the chaperone-mediated proteasome assembly.

Structural modification of the propyl linker of cjoc42 in combination with sulfonate ester and triazole replacements for enhanced gankyrin binding and anti-proliferative activity.

Liver cancer is a complex disease that involves various oncoproteins and the inactivation of tumor suppressor proteins (TSPs). Gankyrin is one such oncoprotein, first identified in human hepatocellular carcinoma, that is known to inactivate multiple TSPs, leading to proliferation and metastasis of tumor cells. Despite this, there has been limited development of small molecule gankyrin binders for the treatment of liver cancer. In this study, we are reporting the structure-based design of gankyrin-binding small molecules which inhibit the proliferation of HuH6 and HepG2 cells while also increasing the levels of certain TSPs, such as Rb and p53. Interestingly the first molecule to exhibit inhibition by 3D structure stabilization is seen. These results suggest a possible mechanism for small-molecule inhibition of gankyrin and demonstrate that gankyrin is a viable therapeutic target for the treatment of liver cancer.

Gankyrin and TIGAR cooperatively accelerate glucose metabolism toward the PPP and TCA cycle in hepatocellular carcinoma.

Oncogene-derived metabolic reprogramming is important for anabolic growth of cancer cells, which is now considered to be not simply rely on glycolysis. Pentose phosphate pathway and tricarboxylic acid cycle also play pivotal roles in helping cancer cells to meet their anabolic and energy demands. The present work focused on gankyrin, a relatively specific oncogene in hepatocellular carcinoma (HCC), and its impact on glycolysis and mitochondrial homeostasis. Metabolomics, RNA-seq analysis, and subsequent conjoint analysis illustrated that gankyrin regulated the pentose phosphate pathway (PPP), tricarboxylic acid (TCA) cycle, and mitochondrial function and homeostasis, which play pivotal roles in tumor development. Mechanistically, gankyrin was found to modulate HCC metabolic reprogramming via TIGAR. Gankyrin positively regulated the transcription of TIGAR through Nrf2, which bound to the antioxidant response elements (AREs) in the promoter of TIGAR. Interestingly, TIGAR feedback regulated the transcription of Nrf2 and subsequently gankyrin by promoting nuclear importation of PGC1α. The loop between gankyrin, Nrf2, and TIGAR accelerated glucose metabolism toward the PPP and TCA cycle, which provided vital building blocks, such as NADPH, ATP, and ribose of tumor and further facilitated the progression of HCC.

Gankyrin activates the hedgehog signalling to drive metastasis in osteosarcoma.

Gankyrin is a regulatory subunit of the 26-kD proteasome complex and promotes the occurrence and progression of many malignancies. However, the role of gankyrin in osteosarcoma (OS) metastasis remains unclear. Hedgehog signalling has been shown to regulate stem cell homeostasis and cancer metastasis, but the mechanisms that activate this pathway in OS are still poorly understood. Here, a series of in vitro and in vivo assays were carried out to explore the function and mechanism of gankyrin regulating Hedgehog signalling in OS. We demonstrated that gankyrin promotes migration, invasion and regulates the expression of some stemness factors by up-regulating Gli1 in OS. Importantly, our data showed an interaction between gankyrin and Gli1. Moreover, gankyrin suppresses the ubiquitin-mediated degradation of Gli1 protein in OS. Gankyrin also significantly promotes the lung metastasis of OS in vivo. Our findings suggest that gankyrin drives metastasis and regulates the expression of some stemness factors in osteosarcoma by activating Hedgehog signalling, indicating that drug screening for compounds targeting gankyrin may contribute to the development of novel and effective therapies for OS.

Structural modification of the aryl sulfonate ester of cjoc42 for enhanced gankyrin binding and anti-cancer activity.

Gankyrin is an oncogenic protein involved in various biological processes, such as cellular growth and proliferation. Its overexpression in certain cancers results in an increase of gankyrin-mediated protein-protein interactions (PPIs), leading to cancer proliferation. To date, only one small molecule (cjoc42) has been identified to bind gankyrin, which simultaneously inhibits its interaction with the 26S proteasome. Despite this advance, 2nd generation inhibitors are needed to improve gankyrin binding and cellular efficacy. To this end, an extensive SAR for the aryl sulfonate ester moiety of the cjoc42 scaffold was explored, and showed that substitutions at the 2-, 3-, and 4-positions manifested significant increases in gankyrin binding, resulting in the most potent binders of gankyrin to date. Subsequent cell-based assay evaluation of our derivatives demonstrated antiproliferative activity against pediatric liver cancer cell lines Hep3B and HepG2, which was not previously observed for cjoc42.

Optimizing the aryl-triazole of cjoc42 for enhanced gankyrin binding and anti-cancer activity.

Gankyrin is an oncoprotein overexpressed in numerous cancer types and appears to play a key role in regulating cell proliferation, cell growth, and cell migration. These roles are largely due to gankyrin's protein-protein interaction with the 26S proteasome. We previously published a study exploring the aryl sulfonate ester of cjoc42 in an effort to enhance gankyrin binding and inhibit cancer cell proliferation. In order to further improve the gankyrin binding ability of the cjoc42 scaffold, an extensive SAR for the aryl-triazole moiety of cjoc42 was developed. Our cjoc42 derivatives exhibited enhanced gankyrin binding, as well as enhanced antiproliferative activity against Hep3B, HepG2, A549, and MDA-MB-231 cancer cell lines.

Deficiency of Gankyrin in the small intestine is associated with augmented colitis accompanied by altered bacterial composition of intestinal microbiota.

BACKGROUND: Gankyrin (GK) is an oncoprotein which regulates inflammatory responses and its inhibition is considered as a possible anti-inflammatory therapy for inflammatory bowel disease (IBD). METHODS: In this study, we investigated the role of GK in epithelial cells using mice with intestinal epithelial cell-specific GK deletion in (i) the entire small intestine and colon (Villin-Cre;Gankyrinf/f) and (ii) the distal intestine and colon (Cdx2-Cre;Gankyrinf/f). RESULT: Unexpectedly, GK-deficiency in the upper small bowel augmented inflammatory activity compared with control mice when colitis was induced with dextran sodium sulfate. Biochemical analyses have revealed GK-deficiency to have caused reduction in the expression of antimicrobial peptides, α-Defensin-5 and -6, in the upper small bowel. Examination of human samples have further confirmed that the reduction of GK expression in the small bowel is associated with colonic involvement in human Crohn's disease. Through the sequencing of bacterial 16S rRNA gene amplicons, bacteria potentially deleterious to intestinal homeostasis such as Helicobacter japonicum and Bilophila were found to be over-represented in colitis induced Villin-Cre;Gankyrinf/f mice when compared to Gankyrinf/f control mice under the same condition. CONCLUSION: These results highlight the distinct site dependence of the pro- and anti-inflammatory functions of GK and provide important insights into the pathogenesis of IBD.

The oncogene Gankyrin is expressed in testicular cancer and contributes to cisplatin sensitivity in embryonal carcinoma cells.

BACKGROUND: Testicular germ cell cancer (TGCC) develops from pre-malignant germ neoplasia in situ (GCNIS) cells. GCNIS originates from fetal gonocytes (POU5F1+/MAGE-A4-), which fail to differentiate to pre-spermatogonia (POU5F1-/MAGE-A4+) and undergo malignant transformation. Gankyrin is an oncogene which has been shown to prevent POU5F1 degradation and specifically interact with MAGE-A4 in hepatocellular carcinoma (HCC) cells. We aimed to investigate the role of Gankyrin in progression from gonocyte to pre-invasive GCNIS and subsequent invasive TGCC. METHODS: We determined Gankyrin expression in human fetal testicular tissue (gestational weeks 9-20; n = 38), human adult testicular tissue with active spermatogenesis (n = 9), human testicular tissue with germ cell maturation delay (n = 4), testicular tissue from patients with pre-invasive GCNIS (n = 6), and invasive TGCC including seminoma (n = 6) and teratoma (n = 7). Functional analysis was performed in-vitro by siRNA knock-down of Gankyrin in the NTera2 cells (derived from embryonal carcinoma). RESULTS: Germ cell expression of Gankyrin was restricted to a sub-population of prespermatogonia in human fetal testes. Nuclear Gankyrin was also expressed in GCNIS cells of childhood and adult pre-invasive TGCC patients, and in GCNIS from seminoma and non-seminoma patients. Cytoplasmic expression was observed in seminoma tumour cells and NTera2 cells. Gankyrin knock-down in NTera2 cells resulted in an increase in apoptosis mediated via the TP53 pathway, whilst POU5F1 expression was unaffected. Furthermore, Gankyrin knock-down in NTera2 cells increased cisplatin sensitivity with an increase in cell death (13%, p < 0.05) following Gankyrin knock-down, when compared to cisplatin treatment alone, likely via BAX and FAS. Our results demonstrate that Gankyrin expression changes in germ cells during normal transition from gonocyte to prespermatogonia. In addition, changes in Gankyrin localisation are associated with progression of pre-invasive GCNIS to invasive TGCC. Furthermore, we found that Gankyrin is involved in the regulation of NTera2 cell survival and that a reduction in Gankyrin expression can modulate cisplatin sensitivity. CONCLUSIONS: These results suggest that manipulation of Gankyrin expression may reduce the cisplatin dose required for the treatment of TGCC, with benefits in reducing dose-dependent side effects of chemotherapy. Further studies are required in order to assess the effects of modulating Gankyrin on GCNIS/TGCC using in vivo models.

The Oncoprotein Gankyrin/PSMD10 as a Target of Cancer Therapy.

Gankyrin (also called PSMD10, p28, or p28GANK) is a crucial oncoprotein that is upregulated in various cancers and assumed to play pivotal roles in the initiation and progression of tumors. Although the in vitro function of gankyrin is relatively well characterized, its role in vivo remains to be elucidated. We have investigated the function of gankyrin in vivo by producing mice with liver parenchymal cell-specific gankyrin ablation (Alb-Cre;gankyrinf/f) and gankyrin deletion both in liver parenchymal and in non-parenchymal cells (Mx1-Cre;gankyrinf/f). Gankyrin deficiency both in non-parenchymal cells and parenchymal cells, but not in parenchymal cells alone, reduced STAT3 activity, interleukin-6 production, and cancer stem cell marker expression, leading to attenuated tumorigenic potential in the diethylnitrosamine hepatocarcinogenesis model. Essentially similar results were obtained by analyzing mice with intestinal epithelial cell-specific gankyrin ablation (Villin-Cre;Gankyrinf/f) and gankyrin deletion both in myeloid and epithelial cells (Mx1-Cre;Gankyrinf/f) in the colitis-associated cancer model. Clinically, gankyrin expression in the tumor microenvironment was negatively correlated with progression-free survival in patients undergoing treatment with Sorafenib for hepatocellular carcinomas. These findings indicate important roles played by gankyrin in non-parenchymal cells as well as parenchymal cells in the pathogenesis of liver cancers and colorectal cancers, and suggest that by acting both on cancer cells and on the tumor microenvironment, anti-gankyrin agents would be promising as therapeutic and preventive strategies against various cancers, and that an in vitro cell culture models that incorporate the effects of non-parenchymal cells and gankyrin would be useful for the study of human cell transformation.

Chronic Microcystin-LR Exposure Induces Hepatocarcinogenesis via Increased Gankyrin in Vitro and in Vivo.

BACKGROUND/AIMS: Our recent study indicated that the serum microcystin-LR (MC-LR) level is positively linked to the risk of human hepatocellular carcinoma (HCC). Gankyrin is over-expressed in cancers and mediates oncogenesis; however, whether MC-LR induces tumor formation and the role of gankyrin in this process is unclear. METHODS: We induced malignant transformation of L02 liver cells via 35 passages with exposure to 1, 10, or 100 nM MC-LR. Wound healing, plate and soft agar colony counts, and nude mice tumor formation were used to evaluate the tumorigenic phenotype of MC-LR-treated cells. Silencing gankyrin was used to confirm its function. We established a 35-week MC-LR exposure rat model by twice weekly intraperitoneal injection with 10 µg/kg body weight. In addition, 96 HCC patients were tested for tumor tissue gankyrin expression and serum MC-LR levels. RESULTS: Chronic low-dose MC-LR exposure increased proliferation, mobility, clone and tumor formation abilities of L02 cells as a result of gankyrin activation, while silencing gankyrin inhibited the carcinogenic phenotype of MC-LR-treated cells. MC-LR also induced neoplastic liver lesions in Sprague-Dawley rats due to up-regulated gankyrin. Furthermore, a trend of increased gankyrin was observed in humans exposed to MC-LR. CONCLUSION: These results suggest that MC-LR induces hepatocarcinogenesis in vitro and in vivo by increasing gankyrin levels, providing new insight into MC-LR carcinogenicity studies.

Inducible liver-specific overexpression of gankyrin in zebrafish results in spontaneous intrahepatic cholangiocarcinoma and hepatocellular carcinoma formation.

Liver cancer is the second leading cause of death worldwide. As such, establishing animal models of the disease is important for both basic and translational studies that move toward developing new therapies. Gankyrin is a critical oncoprotein in the genetic control of liver pathology. In order to evaluate the oncogenic role of gankyrin without cancer cell inoculation and drug treatment, we overexpressed gankyrin under the control of the fabp10a promoter. A Tet-Off system was used to drive expression in hepatocytes. At seven to twelve months of age, gankyrin transgenic fish spontaneously incurred persistent hepatocyte damage, steatosis, cholestasis, cholangitis, fibrosis and hepatic tumors. The tumors were both hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). ICC is the second most frequent primary liver cancer in human patients and the first to develop in this tumor model. We further investigated the role of complement C3, a central molecule of the complement system, and found the expression levels of both in mRNA and protein are decreased during tumorigenesis. Together, these findings suggest that gankyrin can promote malignant transformation of liver cells in the context of persistent liver injury. This transformation may be related to compensatory proliferation and the inflammatory microenvironment. The observed decrease in complement C3 may allow transforming cells to escape coordinated induction of the immune response. Herein, we demonstrate an excellent zebrafish model for liver cancers that will be useful for studying the molecular mechanisms of tumorgenesis.

Gankyrin as a potential therapeutic target for cancer.

Gankyrin is an oncoprotein that plays a central role in the development of cancer. Although researchers have increasingly focused on the relationships of gankyrin with carcinogenesis, metastasis and prognosis of different cancers, the molecular mechanisms are still unclear. In recent years, several interacting partners of gankyrin and cell signaling pathways regulated by gankyrin have been elucidated. In addition, accumulating evidence has indicated the contribution of microRNAs to regulating gankyrin expression in tumor cells. In this review, we summarize the major known roles of gankyrin in cancer cells and highlight the potential clinical relevance of targeting gankyrin. Graphical abstract ᅟ.

Gankyrin promotes the proliferation of gastric cancer and is associated with chemosensitivity.

Although gankyrin is involved in the tumorigenicity and metastasis of some malignancies, the role of gankyrin in gastric cancer is not clear. In this study, we evaluated the function and mechanism of gankyrin in gastric cancer. The effects of gankyrin on gastric cancer growth, proliferation, and chemosensitivity were determined. Gankyrin expression was significantly increased in gastric cancer compared to non-cancerous tissues. This expression significantly enhanced cancer cell proliferation and growth in vitro and in vivo. Suppression of gankyrin downregulated cyclin D1, cyclin E, proliferating cell nuclear antigen, phosphoinositide 3-kinase, AKT, p-PI3K, and p-AKT but upregulated Rb, p53, and p27. However, gankyrin overexpression led to opposite results. Downregulation of gankyrin expression enhanced chemosensitivity to 5-fluorouracil and cisplatin by inducing cell apoptosis. However, upregulation of gankyrin expression led to the opposite outcomes. Gankyrin enhanced gastric cancer cell proliferation by regulating cell cycle-related proteins and by activating PI3K/AKT signaling pathway. Gankyrin played an important role in gastric carcinogenesis and could be a potential effective therapeutic target for enhancing chemosensitivity to 5-fluorouracil and cisplatin.

Clinical Significance of Bmi1 Expression in Inflammatory Bowel Disease.

BACKGROUND: Although the stem cell marker Bmi1 is overexpressed in many malignancies, its role in inflammation-associated cancer is unclear. Colitis-associated cancer (CAC) is caused by chronic intestinal inflammation and often results from refractory inflammatory bowel disease (IBD). METHODS: To assess the involvement of Bmi1 in the development of CAC, we analyzed the gene expression of colon tissues collected from 111 patients with IBD and CAC. RESULTS: In the colonic mucosa of patients with ulcerative colitis, the expression of Bmi1 correlated significantly with the expression of inflammatory cytokines such as IL-6, IL-17, IL-23, and tumor necrosis factor α (TNF-α). In the colonic mucosa of patients with Crohn's disease, the expression of Bmi1 correlated significantly with the expression of TNF-α and IL-23. The expression of Bmi1 was enhanced in the colonic mucosae of refractory IBD, suggesting that Bmi1 expression might be related to increased cancer risk. In addition, patients with high Bmi1 expression showed significantly lower response rates upon subsequent anti-TNF-α therapy as compared to patients with low Bmi1 expression. In human CAC specimens, the expression of Bmi1 was upregulated in nontumor tissues as well as tumors. CONCLUSIONS: Bmi1 expression is related to a refractory clinical course of IBD and upregulated in refractory IBD and CAC. Measurement of Bmi1 expression is a promising approach for the advanced treatment and personalized management of IBD patients.

Correlation of Gankyrin oncoprotein overexpression with histopathological grade in prostate cancer.

Prostate cancer is the second most commonly diagnosed cancer among men worldwide. Identifying new prognostic and predictive biomarkers will help stratification of prostate cancer patients for a better treatment. Gankyrin is a novel oncoprotein which regulates cell cycle and protein degradation. Gankyrin overexpression correlated with the malignant phenotypes and promotes the tumorigenicity and metastasis in many cancers. However, there are not any reports on the role of Gankyrin in prostate cancer. Therefore, this study was designed to investigate the expression of Gankyrin in prostate cancer and analyze its correlation with some clinicopathological characteristics. We characterized the expression of gankyrin in fifty five prostate cancer specimens and twenty non-cancerous tissues by immunohistochemical staining and the results were correlated with clinical characteristics and pathological parameters.Results showed that Gankyrin was expressed in 41 of 55 (74%) prostate cancer patients and its expression was significantly higher than corresponding adjacent normal tissues (p<0.001). Gankyrin overexpression was significantly correlated with histopathological tumor grade, Gleason score and tumor differentiation (P=0.002). These findings showed that Gankyrin is mainly overexpressed in high grade prostate tumors so it may have a significant role in prostate cancer progress and it May serve as a useful biomarker for the identification of aggressive prostate cancers.

Gankyrin regulates cell signaling network.

Gankyrin is an oncoprotein that facilitates the degradation of two key tumor suppressors, namely, Rb and p53. Although Gankyrin overexpression was identified in different carcinomas eventually and associated with poor prognosis, its function and mechanism remain not well understood. Recently, the signal transduction mechanisms of Gankyrin have been explored, which may provide new drug targets in tumors overexpressing Gankyrin. In this review, we summarize the significant signal transduction pathways regulated by Gankyrin.

The co-expression of GPER and Gankyrin in ovarian endometriosis and its correlation with the rASRM stages.

OBJECTIVE: The aim of this study was to examine the expression of G protein-coupled estrogen receptor (GPER) and Gankyrin in ovarian endometriosis, analyze their clinicopathological significance, and investigate their correlation. METHODS: Quantitative real-time polymerase chain reaction and Western blot were performed to testify mRNA and protein expression of GPER and Gankyrin in ovarian endometriosis. Immunohistochemical staining (streptavidin-peroxidase method) was conducted to determine the expression and distribution of GPER and Gankyrin protein in matched ectopic and eutopic endometrium of endometriosis and normal endometrium. We also investigated their associations with rASRM stages and the correlation between the two proteins. RESULTS: GPER and Gankyrin were found overexpressed in ectopic endometrium of endometriosis compared with either its eutopic counterpart or endometrium from normal patients. The immunohistochemical analysis also revealed that higher expression was observed in eutopic endometrium with or without endometriosis during proliferative phase in comparison to secretory phase. These two proteins were positively correlated with the stages of endometriosis. Moreover, a significant positive correlation was found between GPER and Gankyrin both in ectopic and eutopic endometrium of the ovarian endometriosis. CONCLUSION: GPER and Gankyrin might be implicated in the hormonal regulation of endometriosis and be associated with the severity of endometriosis. In addition, GPER and Gankyrin were found to be positively correlated, which could possibly serve as novel therapeutic targets for this disease.

Expression of the oncoprotein gankyrin and phosphorylated retinoblastoma protein in human testis and testicular germ cell tumor.

OBJECTIVE: The oncoprotein, gankyrin, is known to facilitate cell proliferation through phosphorylation and degradation of retinoblastoma protein. In the present study, we evaluated the expression of gankyrin and phosphorylated retinoblastoma protein in human testis and testicular germ cell tumors. METHODS: The effects of suppression of gankyrin by locked nucleic acid on phosphorylation status of retinoblastoma and cell proliferation were analyzed using western blot analysis and testicular tumor cell line NEC8. The expressions of gankyrin, retinoblastoma and retinoblastoma protein were analyzed in 93 testicular germ cell tumor samples and five normal human testis by immunohistochemistry. The retinoblastoma protein expression was determined using an antibody to retinoblastoma protein, Ser795. RESULTS: Gankyrin was expressed in NEC8 cells as well as a normal human testis and testicular tumors. Suppression of gankyrin by locked nucleic acid led to suppression of retinoblastoma protein and cell proliferation in NEC8 cells. Immunohistochemistry of normal testis showed that gankyrin is expressed dominantly in spermatocytes. In testicular germ cell tumors, high expressions of gankyrin and phosphorylated-retinoblastoma protein were observed in seminoma and embryonal carcinoma, whereas the expressions of both proteins were weak in histological subtypes of non-seminoma. Growing teratoma and testicular malignant transformation tissues expressed phosphorylated-retinoblastoma protein strongly, but gankyrin faintly. CONCLUSION: Gankyrin is dominantly expressed in normal spermatocytes and seminoma/embryonal carcinoma, and its expression correlates well with retinoblastoma protein expression except in the growing teratoma and testicular malignant transformation cases. These data provide new insights into the molecular mechanisms of normal spermatogenesis and pathogenesis of testicular germ cell tumors.

Synthesis and evaluation of 2,5-substituted pyrimidines as small-molecule gankyrin binders.

Background: Gankyrin is an ankyrin-repeat protein that promotes cell proliferation, tumor development and cancer progression when overexpressed. Aim: To design and synthesize a novel series of gankyrin-binding small molecules predicated on a 2,5-pyrimidine scaffold. Materials & methods: The synthesized compounds were evaluated for their antiproliferative activity, ability to bind gankyrin and effects on cell cycle progression and the proteasomal degradation pathway. Results: Compounds 188 and 193 demonstrated the most potent antiproliferative activity against MCF7 and A549 cells, respectively. Both compounds also demonstrated the ability to effectively bind gankyrin, disrupt proteasomal degradation and inhibit cell cycle progression. Conclusion: The 2,5-pyrimidine scaffold exhibits a novel and promising strategy for binding gankyrin and inhibiting cancer cell proliferation.

Gankyrin-mediated interaction between cancer cells and tumor-associated macrophages facilitates prostate cancer progression and androgen deprivation therapy resistance.

Increasing evidence reveals that the interaction between tumor cells and tumor-associated macrophages (TAMs) facilitates the progression of prostate cancer, but the related mechanisms remained unclear. This study determined how gankyrin, a component of the 19S regulatory complex of the 26S proteasome, regulates the progression and androgen deprivation therapy (ADT) resistance of prostate cancer through tumor cell-TAM interactions. In vitro functional experiments and in vivo subcutaneous tumor models were used to explore the biological role and molecular mechanisms of gankyrin in prostate cancer cell-TAM interactions. 234 prostate cancer patients were randomly divided into training and validation cohorts to examine the prognostic value of gankyrin through immunohistochemistry (IHC) and statistical analyses, and high gankyrin expression was correlated with poor prognosis. In addition, gankyrin facilitated the progression and ADT resistance of prostate cancer. Mechanistically, gankyrin recruited and upregulated non-POU-domain-containing octamer-binding protein (NONO) expression, resulting in increased androgen receptor (AR) expression. AR then bound to the high-mobility group box 1 (HMGB1) promoter to trigger HMGB1 transcription, expression, and secretion. Moreover, HMGB1 was found to promote the recruitment and activation of TAMs, which secrete IL-6 to reciprocally promote prostate cancer progression, ADT resistance and gankyrin expression via STAT3, resulting in formation of a gankyrin/NONO/AR/HMGB1/IL-6/STAT3 positive feedback loop. Furthermore, targeting the interaction between tumor cells and TAMs by blocking this loop inhibited ADT resistance in a tumor xenograft model. Taken together, the data show that gankyrin serves as a reliable prognostic indicator and therapeutic target for prostate cancer patients.